Category Archives: Research & Trends

Understanding Dementia and Medical-Legal Implications

By Sanjay Adhia, M.D.

 Dementia encompasses degenerative disorders to the brain. It can be subtle and fluctuate in severity even from day to day. It can accompany genetic factors, or be associated with an injury or repeated injuries to the brain and head. It is serious and marked by symptoms that can impair making informed decisions or manage the most basic tasks we take for granted in living our daily lives. 

 What does “Dementia” Mean?

Dementia is formally known as a “Neurocognitive Disorder,” or NCD. It is described by the CDC as a “general term for the impaired ability to remember, think, or make decisions that interferes with doing everyday activities.” [1]

 Diagnosing and Stages of Dementia

Dementia has a variety of stages, from Mild to Major.[2] Dementia itself is not a disease, but rather a broad term that encompasses several conditions, including Alzheimer’s disease.

There are distinct elements to the stages and diagnoses of Dementia [3]. For example, Mild Cognitive Impairment [4] is the transition from normal aging to more serious decline into Dementia.

Disease of the Elderly

Dementia is usually seen in older people. However, while some elderly people may have mild age-related cognitive decline, most do not develop Dementia. This is not to say that young people never develop Dementia, but the reasons are usually different and not as common.

Thinking Clearly

Regardless of the age of a person with Dementia, this serious condition can impact a person’s ability to make important decisions that require clarity of thought. Arguably, a person is impaired if they no longer can lucidly think through the benefits and consequences of a decision.

Informed Decisions, Dementia and Competency

If a person with Dementia is making a will or trust, selling real estate or a business, or making gifts of money, art or other tangible items, the potential legal consequences are troubling. Signing or revoking a financial power of attorney are also acts that require competency, as is signing or revoking a medical power of attorney, sometimes called a “living will.”

Assessing if Dementia is or is not present is a job for a physician qualified to assess neurocognitive disorders. Everyone, including doctors, are alerted by signs and symptoms that raise the possibility Dementia is present.

Signs and Symptoms

Dementia involves problems with memory, attention, communication, reasoning and visual perception. Signs of Dementia may include:

  • getting lost in a familiar neighborhood
  • forgetting the name of someone close
  • forgetting cherished memories
  • losing the ability to complete tasks independently, such as activities of daily living (ADLs) or instrumental activities of daily living (IADLs)
  • confusion that is out of character
  • personality or behavior changes
  • apathy and withdrawal
  • depression
  • paranoia
  • difficulty with balance, walking and eating
  • incontinence
  • communication impairments, struggling with word choice, changed mastery of vocabulary, aphasia (loss of ability to understand or express speech)

Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL)

How we cope with a daily routine of tasks can change when Dementia is present. This figure illustrates the differences between ADLs and IADLs. Dementia can impact both. Difficulty carrying out ADLs or IADLs may be an alert that a physician should assess if Dementia is present or in the early stages. Dementia can be severely disabling when people cannot perform the basic tasks of life, from bathing to paying bills.


There are many disorders and conditions that result in the loss or damage of neurons and their connections in the brain, leading to Dementia.

This table contains some of the most common causes or features of conditions associated with Dementia, such as Alzheimer’s Disease, Lewy Body Dementia, Stroke (Vascular Dementia), Parkinson’s Disease, TBI, and others.

Alzheimer’s Disease Most common cause of Dementia (60–80{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} of all cases). Symptoms include initial loss of recent memory, later loss of remote memory, and eventual personality changes and difficulty with walking and talking.
Vascular Dementia 10{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} of Dementia cases are caused by strokes or other vascular problems. Progresses in a stepwise fashion with sudden drops in functioning.
Parkinson’s Disease Dementia Parkinson’s Disease Dementia and Lewy Body Dementia result in memory deficits. There may also be movement or balance problems such as stiffness or trembling. Additional symptoms may include changes in alertness, visual hallucinations, and insomnia.
Fronto-temporal Dementia (FTD) There often are prominent changes in personality and behavior leading to impaired judgment and inappropriate behavior. Problems with language skills may also be present.
Mixed Dementia Some people with Dementia who are typically 80 or over may have a combination of conditions causing their Dementia, such as concurrent Alzheimer’s disease and Vascular Dementia.
Reversible Causes [6] Dementia can be due to a reversible cause such as medication side effects, increased brain pressure, thyroid hormone abnormality, subdural hematoma, brain cancer, infections, poisoning, normal-pressure hydrocephalus, anoxia, or vitamin deficiency.
Other Causes Other causes of Dementia may include Traumatic Brain Injury (TBI), Huntington’s disease and Creutzfeldt-Jakob disease. TBI and mTBI (mild TBI, i.e., concussions) can lead to Dementia. We see this in sports injuries like repeated concussions in boxers or football players.



Diagnosing Dementia involves a clinical exam with a history and physical along with a mental status exam. The workup may also include labs, neuroimaging (such as an MRI [7]) and neuropsychological testing.

Psychiatrists, neurologists, geriatricians and physical medicine and rehabilitation (PMR) doctors are the specialists who generally diagnose Dementia. Neuroradiologists can assist with the diagnosis.

Neuropsychological tests administered by a qualified licensed neuropsychologist can be helpful to the physician in diagnosing Dementia.

Many physicians, myself included, are trained and certified to perform the Montreal Cognitive Assessment (MoCA), a frontline screening test. The MoCA is a cognitive screening test designed to detect mild cognitive impairment (MCI) and Alzheimer’s disease. Administering the MoCA is a decision for a neuropsychologist or physician certified to do so. A MoCA is not indicated in every case. It is worth noting that neuropsychological testing or neuroimaging in and of itself may not be sufficient to render a diagnosis.

Delirium vs. Dementia

It is important to be able to distinguish Delirium from Dementia. Delirium is generally caused by a medical condition or toxicity. Often, they can co-occur. Generally, Delirium is characterized by:

  • Acute onset
  • Fluctuating course
  • Altered consciousness

Typically, Dementia has a more gradual onset and progressive course and is usually with intact consciousness.


Treatment for Dementia depends on the cause. Some causes, like Alzheimer’s Disease, have no cure, but there are treatments that can modestly improve cognition in some individuals or slow the rate of decline.

Additionally, there are medications that can be useful in protecting the brain or helping with mood or behavioral disturbances.

Maintaining a healthy lifestyle with diet and exercise and maintaining social contacts can be preventive.

Dementia and Medical-Legal Implications

Dementia can impact a variety of cognitive domains and other abilities. It may result in changes in competency or behavior.

People of all ages are used to making decisions, presumably informed and logical. 

Civil litigation and criminal cases generally involve decision-making moments. If Dementia in any way impairs a person’s competency, the Trier of Fact is better able to make a judgment when a forensic evaluation is conducted to determine if a Neurocognitive Disorder like Dementia is a factor. Thus, Dementia may present with a variety of medical-legal consequences.

Malpractice and Medical Negligence

Some individuals with Dementia are in institutional settings such as nursing homes, assisted living, or geriatric psychiatric facilities where there could be instances of medical malpractice.

In fact, Dementia can interfere with a person’s ability to assess their own medical care and/or report malpractice or negligence. In advanced Dementia, self-advocacy is unlikely if not impossible.

Negligence in care is not limited to medical treatment. Those with Dementia may also have a higher risk of falls due to multiple reasons, including getting lost or the effects of medications. Staff in facilities caring for those with Dementia will benefit from training about such risks.

Additionally, certain medications, both prescribed and over-the-counter, can complicate or worsen Dementia. Impairment in cognition, for example, can co-occur with the use of certain prescription or over-the-counter medications, such as oral antihistamines like Benadryl (with anti-cholinergic activity)[8]. Caregivers need to be aware of these concerns.

Disability: Impact on Life and Work

Those with Dementia may have decreased ability to perform work-related duties. A Fitness for Duty or other occupational evaluation may be appropriate in such a situation.

Many jobs require appropriate behavior and interpersonal functioning, which may be problematic with those with Dementia. Additionally, adequate memory is necessary for many essential job functions, i.e. fundamental tasks to perform one’s job.

Some of the moderate and severe cases of Dementia involve individuals who have decreased ability to perform activities we take for granted. The chart above does an excellent job of demonstrating activities of daily living that can be diminished by Dementia, ranging from basic hygiene to balancing a checkbook.

Contractual Competency

Individuals with Dementia may lack capacity to execute contracts, which could include:

  • irrevocable or revocable trust
  • life insurance trust (irrevocable)
  • sale of an asset
  • purchase of an asset
  • obtaining a loan or refinance on real property

Testamentary Capacity [9]

Those with Dementia may not be able to understand the prerequisite elements of a will. In many will-contest cases, the individual in question is deceased. When the estate is being distributed, unexpected bequests may lead beneficiaries to wonder if the testator (person making the will) was competent when they signed the document.

To determine testamentary capacity posthumously requires some detective work to opine on the person’s mental state in the past. If an autopsy is ordered, the deceased’s brain and other findings may provide clues about Dementia or other neurocognitive disorders.

In addition, a close review of medical records and collateral interviews with the deceased’s treating physicians, family, friends or caregivers are always a consideration for the forensic evaluator. As a Forensic Psychiatrist, I also scrutinize the observations of anyone who benefits emotionally or financially.

Undue Influence

Those with Dementia are emotionally and cognitively susceptible to undue influence. Undue influence is often litigated with questions of testamentary capacity.

Probate litigation may address a range of behaviors by the testator that give rise to the legal conflict. The behavior of others around the testator may also be relevant to the extent they appear to manipulate or control the testator with Dementia.

Just because a person has Dementia does not mean they will be unduly influenced for someone else’s gain. However, it is a risk factor.

Undue influence is complex. Psychological and medical factors are usually at play, and a detailed discussion is outside the scope of this article.


Scams can seek to exploit diminished cognitive capacity in the elderly. Above I identify several ways in which Dementia can manifest. For example, “Confusion that is out of character” may cause a person to believe an unlikely “story” that involves transferring money to someone they do not know. Another form of fraud is manipulating a person to sell or give away their assets in an uncharacteristic manner. This does not have to be a family member, though that may be the case.

The capacity for self-advocacy and critical thinking is crucial to defend against fraud.

Elder Abuse

Those with dementia could be susceptible to elder abuse. Elder abuse can involve physical abuse, psychological abuse, sexual abuse, financial exploitation, medication abuse, passive or active neglect.

Criminal Cases: Competency, Dementia and Culpability

Dementia may influence alleged criminal acts or lead to incompetency to stand trial. It is important to remember that dementia is not only seen in the elderly. Brain injuries are believed to be associated with early onset dementia, for example. As a result it is possible dementia is a factor in competency to stand trial or culpability.

Unlike some cases of incompetency due to schizophrenia, those with Dementia are generally more likely to be unrestorable (e.g., treatment will not restore them to be competent to stand trial). Dementia may provide the basis for an insanity defense or sentence mitigation. In some states, such as Texas, a forensic certification in psychiatry or psychology is required to opine in Insanity or Competency to Stand Trial cases. Geriatric psychiatrists and neurologists without forensic certification would not be permitted in some states to opine on these questions.

Choosing a Dementia Expert

In choosing an expert witness for cases involving Dementia, take note of the expert’s background.

It may appear logical to an attorney with a case involving claims of Dementia to consider an expert in Dementia-related medical specializations. Note that diagnosis and treatment is the training of those Board-Certified in specializations such as geriatric medicine, Neurology, Internal Medicine, Psychiatry and others.

However, in treatment-focused medical specializations, no training is received in medico-legal considerations. This can have consequences in a lawsuit.

Training in medical diagnosis and treatment does not include application to medico-legal considerations. As a result, a physician may arrive at a diagnostically sound opinion that is not helpful to a jury considering a legal matter with complex and unique features and consequences.

Forensic Psychiatry is the only medical specialization that addresses the interface of psychiatry and law, e.g., interpreting and opining about complex medical-legal features relevant in a lawsuit.

A doctor Board-Certified in Forensic Psychiatry with further subspecialty certification in brain diseases, i.e., Brain Injury Medicine, may be a better expert witness than a physician with other specializations.

If more than one physician in complementary specialties best serves a jury or judge, a team of a Forensic Psychiatrist and another specialist may be indicated, depending on the complexity of the case.

Although neurologists are adept at treating Dementia and the neurological causes of Dementia, they may not have the experience to evaluate the psychiatric complications of Dementia, which can have the types of medical-legal implications described in this article.

As a Forensic Psychiatrist Board-Certified in Brain Injury Medicine, I regularly treat both the psychiatric and neurocognitive manifestations of Dementia due to TBI, stroke and other neurological conditions. In addition to NCD due to TBI, which is of more immediate onset, TBI can elevate the risk of developing Alzheimer’s disease years after the brain injury. My patients at TIRR Memorial Hermann include individuals who may have developed an NCD after, for example:

  • A severe blow to the head, such as in a car accident or fall. Traumatic brain injury can occur.
  • A stroke that could result in a Vascular Dementia.
  • Repeated concussions (mTBI) like those suffered by an athlete in a sport where brain injuries are a significant risk. This is described by some as causing Chronic Traumatic Encephalopathy (CTE), though research is inconclusive.

In summary, it would be advisable to retain an expert who has both medical-legal expertise in conducting IMEs, such as a Board-Certified Forensic Psychiatrist, and experience in treating those with Dementia. Testamentary capacity and Undue Influence are legal concepts with unique features relevant in a lawsuit but not in treatment.


Dementia is a neurocognitive disorder that can profoundly impact a person’s quality of life, independence, and ability to make decisions. Scientists and doctors continue to research the causes and risks of Dementia to help discover effective ways to treat and prevent it.

As competency is a feature of many adjudicated matters, Dementia has numerous medical-legal implications. If Dementia is a possible factor in a case, the Trier of Fact may wish to have this assessed with a forensic evaluation conducted by a qualified physician.

The original article can be found here:


Author Bio


Dr. Adhia is a triple Board-Certified Psychiatrist in Forensic Psychiatry, Psychiatry and Brain Injury Medicine. He is a practicing neuropsychiatrist and clinical psychiatrist.  Dr. Adhia is fascinated by the unique interface of neuropsychiatry and the law. His interests led him to obtain experience and Board Certification in Brain Injury Medicine. He treats patients with brain injuries, strokes, spinal cord injuries and other neurological disorders at TIRR Memorial Hermann, a teaching hospital in Houston and national leader in neurorehabilitation. Many of the patients with TBI and stroke have Dementia along with anxiety disorders and mood disorders. Research also suggests a correlation between spinal cord injuries and Dementia.[10] Some of his patients have rare neurological disorders that could cause Dementia, such as brain cancer and hydrocephalus. Other conditions such as multiple sclerosis may not cause NCD but can cause some neurocognitive deficits.  Dr. Adhia explains more about Brain Injury Medicine on his site and Brain Injuries in particular in Brain Injuries Explained.      

Sanjay Adhia, M.D., Forensic Psychiatrist (832) 746-5905


I encourage readers to learn more about Dementia. Here are some sources you may find interesting. This is not an endorsement of the sources’ validity.

  1. Centers for Disease Control and Prevention. What Is Dementia? (2019, April 5). Retrieved from
  2. American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders(5th ed.), p. 602.
  3. Mayo Clinic. Dementia: Symptoms and causes. (2021, June 17). Retrieved from
  4. Mayo Clinic. Mild cognitive impairment (MCI). (2020, September 02). Retrieved from
  5. Legislative Analyst’s Office. A Long-Term Outlook: Disability Among California’s Seniors. The California Legislator’s Office Non Partisan Research Fiscal and Policy Advisor, p. 6. Retrieved from
  6. Op cit.
  7. Chandra, A., Dervenoulas, G., Politis, M. et al. (2019). Magnetic resonance imaging in Alzheimer’s disease and mild cognitive impairment. Journal of Neurology, 266, 1293–1302.
  8. ElderConsult. Anticholinergic Meds. (2019, September 9). Retrieved from
  9. The term “testamentary capacity” is often used in connection with the signing of a will. In fact, a will may not be the guiding instrument to distribute a person’s estate. The term “testamentary capacity” is used here to generally describe questions of competency that apply to estate planning decisions.
  10. Huang, S. W., Wang, W. T., Chou, L. C., Liou, T. H., & Lin, H. W. (2017). Risk of Dementia in Patients with Spinal Cord Injury: A Nationwide Population-Based Cohort Study. Journal of Neurotrauma, 34(3), 615–622.
a 3D printer printing a hand

3D Exhibits May Help Jurors Understand an Expert’s Technical Testimony

Lawyers depend upon expert witnesses to convey their opinions in clear language, breaking down complex ideas into digestible portions that juries and judges can comprehend. While words are an expert witness’ primary tool, juries understand evidence more readily when they can visualize a concept.

Studies suggest that people are more likely to understand new information when it is presented both in narrative and visual form.  Brains process information more effectively when they are stimulated simultaneously though multiple senses, including hearing and seeing.

Demonstrative Evidence

An expert’s visual evidence may be real or demonstrative. Real evidence (also known as physical or evidence) is an object that is material to the litigation. A dented fender with a paint transfer or a fragment of a device that exploded are examples of real evidence. Experts exhibit real evidence to juries while explaining how an examination or study of the evidence caused the expert to form particular opinions.

Demonstrative evidence is a representation of real evidence. Demonstrative evidence depicts a scene, object, or condition as it actually existed. Photographs of an accident scene or an x-ray of a broken bone are examples of demonstrative evidence. Experts use those exhibits to assist their narration of opinions just as they would use real evidence.

Expert witnesses have historically prepared diagrams or drawings to illustrate their testimony. A spinal surgeon might draw a picture of vertebrae to illustrate where an injury occurred, while an accident reconstruction engineer might use a diagram to pinpoint the location of skid marks or debris at an accident scene. 

Because they are familiar to lawyers and courts, diagrams and drawings are usually uncontroversial. The expert will testify that the exhibit accurately depicts the thing it represents and, while the opposing party is free to challenge that testimony on cross-examination, the jury will usually be allowed to see the exhibit if the expert affirms that is a reasonably accurate representation of the facts and if the court finds that it is not misleading or otherwise prejudicial.

Visualization Evidence

Some demonstrative evidence is intended to allow juries to visualize events described by eyewitnesses or deduced by experts. An animation that demonstrates how an accident occurred (or how an expert believes it must have occurred) allows a jury to visualize the accident rather than relying solely on an explanation of a diagram.

As technology has become more sophisticated, so has demonstrative evidence. Three-dimensional visualizations — commonly used by architects to allow a virtual “walk through” of a planned home — allow experts to change the viewer’s perspective so that a scene can be observed from different angles or perspectives. The explosion of 3D printer technology allows experts to build models of objects to exacting specifications.

Like most people, judges tend to resist change. Judges were once wary of technology creeping into the courtroom. Each new generation of judges, however, has been more accepting of technology that has now become commonplace. While judges were once skeptical about animations, most judges now allow experts to illustrate their opinions with animated evidence if the expert authenticates the animation by testifying that it fairly and accurately represents the expert’s conclusions.

3D Evidence and Verdicts

While studies suggest that demonstrative evidence helps juries understand complex testimony, it is less clear whether 3D visualizations are more helpful to juries than photographs as jurors attempt to understand an expert’s testimony. A forensic scientist, a psychologist, and two colleagues designed an experiment to determine the impact that different kinds of visual evidence have on juries.

The authors conducted mock trials before randomly selected individuals who played the role of jurors. They presented evidence to different jurors using three kinds of demonstrative evidence. Testimony established that two men left a tavern together. One of the men fell and died after suffering a serious skull fracture. The question for the jury was whether the victim fell accidentally or was pushed.

A forensic anthropologist testified as an expert witness for the prosecution. The juries heard the same recorded testimony in each trial. The expert used technical language to explain the damage to the victim’s skull.

The experimenters varied the nature of the visual evidence that was shown to the jury as the expert testified. In one set of trials, the jurors saw a photograph of the victim’s skull. In a second set of trials, the jurors viewed a 3D visualization of the same skull. In the third set of trials, the jurors considered a 3D printed model of the skull. The skull was circulated among the jurors, allowing them to touch and examine the exhibit, during the expert’s testimony.

The jurors did not deliberate. Instead, each juror completed questionnaires at the end of the trial. About three-fourths of the jurors who viewed the photograph or the 3D visualization would have returned a “not guilty” verdict, while only 55{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} of jurors who saw the 3D printed model would have acquitted.

The experimenters were cautious about attributing significance to the trial outcome as the experiment was not designed to test whether (as other studies have suggested) demonstrative evidence may induce a pro-prosecution outcome in criminal trials. The experimenters did note that jurors who handled the 3D printed model were more likely to conclude that the amount of force required to damage the skull was indicative of guilt. 

Since the expert gave no testimony about the amount of force needed to cause skull trauma, the experimenters suggested that caution should be exercised in allowing jurors to handle 3D printed models of evidence. Perhaps the handling of a skull evoked an emotional response that made jurors more likely to view a defendant as guilty. 

3D Evidence and Comprehension

The experimenters asked whether jurors understood the visual evidence and how the visual evidence helped jurors understand the expert’s testimony. About three-quarters of the jurors found the exhibit itself to be comprehensible, regardless of its nature, although jurors were slightly more likely to understand the 3D printed model.

More importantly, the experimenters found that 79{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} of jurors who viewed the photograph thought they understood the expert’s technical language. The use of 3D technology improved the jurors’ understanding of the expert’s jargon. When jurors viewed a 3D visualization of the skull, 88{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} of jurors thought they understood the expert’s language. When jurors viewed the 3D printed model, 94{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} of jurors said they understood the expert’s technical testimony.

The experimenters suggested that the study might offer evidence that jurors are less likely to misinterpret an expert’s testimony when the experts use 3D reconstructions to explain the terms that they use. The study might also suggest that jurors place greater weight on conclusions they draw from 3D exhibits than they place on conclusions drawn from the expert’s testimony. 

On the whole, the study offered some evidence that 3D exhibits help jurors understand an expert’s technical language. Lawyers may wish to consider 3D exhibits as an alternative to photographic evidence or diagrams if experts feel comfortable using those exhibits to explain their opinions.


Will AI Replace Expert Witnesses?

Fans of science fiction are familiar with the role that Artificial Intelligence (AI) might eventually play in our daily lives. Even in the present, machines are being programmed to simulate intelligence by learning, adapting, and making reasoned decisions that respond to new situations.

Self-driving cars create the illusion of intelligence because they use algorithms to make decisions based on constantly changing data. Doctors depend on AI to help them diagnose health conditions, a task that machines may eventually be able to perform more accurately than physicians and without their assistance. Electronic tutors help children learn by assessing whether a student is bored or struggling and by changing lessons to meet the student’s needs.

Some have suggested that lawyers and judges will eventually be replaced by AI counterparts. Legal reasoning might even by improved by removing bias and political leanings from the decision-making process. 

Jurors cannot be replaced by machines without amending federal and state constitutional guarantees of jury trials. Whether it would be wise to remove human emotion from the process of rendering a verdict probably depends on how lawyers feel about humans.

Expert Witnesses and AI

Matthew Robert Bennett and Marcin Budka have been “investigating the potential for AI to study evidence in forensic science.” Their results have been mixed. Focusing on the ability of AI to analyze footprint evidence, they found that the AI “was better at assessing footprints than general forensic scientists, but not better than specific footprint experts.”

Footwear imprints are commonly found at crime scenes. The FBI contends that “footwear impression evidence often provides an important link between the suspect and the crime scene.”

Forensic investigators gather shoeprint or footprint evidence at crime scenes. Forensic experts then offer opinions about their source. Scientists warn that prints found at crime scenes are often of low quality and that methods used to take impressions of the prints may change their characteristics. “For this reason, there will always be some uncertainty concerning whether a suspect’s shoe truly matches the crime scene print, or if the match is simply a false positive.”

Training an AI to Be an Expert

Footprint experts may be able to determine a suspect’s height, weight, and gender from the size of his or her footprints. However, Bennet and Budke determined that podiatrists have a 50{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} success rate when they determine gender based on footprints — the same success rate that guessing would produce. 

Bennet and Budke trained an AI to perform the same task. The AI arrived at a correct conclusion about gender 90{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} of the time.

Shoeprint experts rely on experience and databases to identify the make of a suspect’s shoe. Bennet and Budke concluded that true experts are rarely mistaken in their identification. Unfortunately, there are few true footwear experts in the UK, where Bennet and Budke conducted their study.

Forensic investigators and police detectives make use of the UK’s extensive database of footwear and shoeprints. They are much less successful than experts at identifying footwear from shoeprints. Bennet and Budke tried to determine whether an AI could do a better job.

They trained a second AI to identify the make and model of footwear from black and white photographs of shoeprint impressions. They ran several trials with casual database users and discovered that their success rate varied from 22{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} to 83{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4}. When they ran the same trials with their AI, the success rate varied from 60{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} to 91{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4}. 

The AI was better than database users who were not among the UK’s elite footwear experts, but still had a significant error rate. Actual footwear experts performing the same trial were nearly always right. The lesson learned is that AI isn’t yet ready to supplant human experts, at least when it comes to footwear identification — and that detectives who fancy themselves to be experts are not remotely qualified to render accurate opinions.

AI in Court

Perhaps R2D2 will one day be allowed to testify as an expert witness. At present, courts don’t need to grapple with the ability of an AI to swear an oath. As filtered through human witnesses, however, evidence created by an AI can influence the outcome of trials.

ExpertPages recently discussed the perils of relying on ShotSpotter, a form of AI that uses algorithms to deduce the location of loud noises that it identifies (not always correctly) as gunshots. Even if the accuracy of ShotSpotter were a given, the ability of humans to tweak the results that algorithms produce raises questions about the reliability of ShotSpotter. Investigations by journalists have “identified a number of serious flaws in using ShotSpotter as evidentiary support for prosecutors.”

Apart from the potential unreliability of human witnesses who present the conclusions drawn by AI, the accuracy of an AI’s conclusions depends on the reliability of the algorithm that teaches the AI to “think.” The creators of AI generally claim a proprietary interest in the algorithms, refusing to open them for inspection by an opposing party. That makes “trust us” the common fallback position of human witnesses who explain how an AI reached its conclusions.

In cases that depend on evidence generated by an AI, opposing parties may need to hire an AI expert. The expert will likely have a background in computer science or information technology but might need to work with a second expert who has specialized knowledge of biomechanics, e-commerce, or a variety of other disciplines, such as footwear recognition or acoustics. While the goal of AI is to improve the human condition by allowing computers to arrive at faster and more accurate conclusions than humans, the present reality is that human experts are often needed to testify about the flaws in AI decision-making.

Expert Testimony May Be Necessary to Counter ShotSpotter Evidence

The latest technology to capture the attention of law enforcement is called ShotSpotter. The manufacturer claims that hidden microphones installed in neighborhoods can tell the difference between gunshots and other loud noises. Rather than waiting for someone to report a shooting, police agencies that rely on the technology dispatch officers to the location where the shots were allegedly fired.

The technology has generated criticism. Apart from concerns about the concentration of microphones in black neighborhoods, the Electronic Frontier Foundation is worried that police agencies might use the microphones to eavesdrop on private conversations. Whether the ShotSpotter system reduces gun violence seems doubtful. 

From the standpoint of an expert witness blog, the question is whether defense attorneys should use expert witnesses to challenge ShotSpotter evidence in court. There is good reason to think that Daubert challenges should be filed, and experts employed, whenever ShotSpotter evidence is a critical component of the prosecution’s proof.

Investigations of ShotSpotter 

A recent investigation calls into question the evidentiary value of ShotSpotter reports. Last year, Michael Williams brought a shooting victim to a Chicago hospital. Williams said the victim was shot during a drive-by shooting. After the victim died, the police arrested Williams for the victim’s murder. Why Williams would bring the victim to a hospital if Williams intended to kill him is a question that raises serious doubt about Williams’ guilt.

The police built their case on video and ShotSpotter evidence. The video evidence showed only that Williams’ car had stopped in the 6300 block of South Stony Island Avenue at 11:46 p.m. on the night of the shooting. The police contended that the victim was shot at that location. No video evidence supports that contention.

The police contend that they received a “shots fired” alert from ShotSpotter at the Stoney Island location. In fact, company records show that “19 ShotSpotter sensors detected a percussive sound at 11:46 p.m. and determined the location to be 5700 South Lake Shore Drive—a mile away from the site where prosecutors say Williams committed the murder.” The company’s algorithms identified the sound as an exploding firework.

Company records show that “a ShotSpotter analyst manually overrode the algorithms and ‘reclassified’ the sound as a gunshot.” Months later, a different ShotSpotter employee manually changed the alert’s coordinates to a South Stony Island Drive location near the place where Williams’ car can be seen on camera.

The evidence suggests that ShotSpotter changed its data to support the theory that Williams shot the victim. Williams’ lawyer filed a motion that challenged the ShotSpotter evidence, arguing that it failed to meet the Illinois standard for the admissibility of expert opinions. Rather than defending against the motion, prosecutors agreed not to use ShotSpotter evidence against Williams. 

Daubert Challenges to ShotSpotter Evidence

The investigation suggests that the Chicago incident was not an isolated example of ShotSpotter tailoring its conclusions to match law enforcement theories. In a carefully worded statement, ShotSpotter denied that it has ever “altered the information in a court-admissible detailed forensic report based on fitting a police narrative.” The statement claims that ShotSpotter is “100{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} accurate,” a claim of certainty that many reputable forensic science experts condemn. The statement asserts that ShotSpotter has been admitted over ten Frye challenges and one Daubert challenge, but it does not state how many challenges to admissibility have succeeded.

ShotSpotter commissioned a report by CSG Analysis, a “police officer-owned and operated company,” that is filled with unsurprising praise of ShotSpotter. The report does not purport to be based on a scientific analysis. Rather, it is based on interviews with police officers in cities that have paid to install ShotSpotter. 

Despite the report’s obvious credibility issues, the authors acknowledge that false positives — sounds that could be caused by trucks, dumpsters, construction, church bells, and all the other sources of concussive sound — are a significant operational problem with ShotSpotter. In two of the seven jurisdictions where interviews were conducted, half of the ShotSpotter alerts were believed to be false positives. A recent study found that Chicago police officers investigated 40,000 ShotSpotter alerts in a 21-month period that resulted in no evidence that shots had been fired.

Challenges to ShotSpotter Evidence

ShotSpotter claims that its analysts can identify actual gunshots when evidence is needed for court. The analysts allegedly perform a deeper dive into the data than the system’s algorithms perform. ShotSpotter contends that a more reliable human analysis explains why results are changed after police agencies contact ShotSpotter. Since one purpose of algorithms is to eliminate human bias, one might wonder whether second-guessing algorithms calls either the algorithms or the analyst’s opinions into question.

The admissibility of ShotSpotter evidence, whether generated by algorithms or humans, is not a foregone conclusion. A Daubert challenge should focus on whether ShotSpotter results been accepted by any independent scientific community, whether its analytical system has been peer reviewed, whether it has a known error rate, and whether conclusions drawn by analysts have been verified by independent testing. The National Juvenile Defender Center has compiled materials, including transcripts of testimony that ShotSpotter witnesses have given at Daubert/Frye hearings, that may guide those challenges.

Notably, a California appellate court reversed a conviction based on ShotSpotter evidence because the trial court did not hold a pretrial hearing to determine whether the evidence was reliable. The court noted the dearth of appellate opinions considering the admissibility of ShotSpotter evidence and concluded that courts could not assume the reliability of the novel technology.

ShotSpotter offers to supply prosecutors with expert witnesses who will testify in court for $350 an hour with a two-hour minimum. Retaining a defense expert with a background in acoustic science may be critical to countering those experts and to bringing a successful Daubert challenge. 

Disabled man, wheelchair

Suit Claims Requiring Disabled Attorneys to Present Experts is Discriminatory

A new suit filed in California district court claims that the California State Bar discriminates against attorneys with mental disabilities by requiring them to present expert witnesses to attest to their condition when they are facing discipline.

The Requirement

The Rules of Procedure of the State Bar of California outlines ten mitigating factors that a respondent may rely upon in disciplinary proceedings. Standard 1.6(d) specifies that “Mitigating circumstances may include:…(d) extreme emotional difficulties or physical or mental disabilities suffered by the member at the time of the misconduct and established by expert testimony as directly responsible for the misconduct, provided that such difficulties or disabilities were not the product of any illegal conduct by the member, such as illegal drug or substance abuse, and the member established by clear and convincing evidence that the difficulties no longer post a risk that the member will commit misconduct.”

The Lawsuit

On June 24, 2021, Michael Potere filed a lawsuit against The Board of Trustees of the State Bar of California and Donna S. Hershkowitz, the Interim Executive Director of The Board of Trustees of the State Bar of California.

Potere is disabled according to the definition provided by the Americans with Disabilities Act, which defines disability as “a physical or mental impairment that substantially limits one or more of the major life activities” or the individual in question and “mental impairment” to include “any mental or psychological disorder, such as…emotional or mental illness.” Potere has been diagnosed by numerous medical professionals as suffering from depression or major depression.

Potere claimed that he was harmed by Standard 1.6(d) because he was financially unable to hire an expert witness in his California State Bar Court proceedings. Because he was unable to provide an expert witness, the Hearing Department and the Review Department both found that Potere failed to prove that his mental disability caused his misconduct.

In his suit, Potere claimed that Standard 1.6(d) discriminated against persons with disabilities because it is the only group of respondents who are required to use expert testimony to establish a mitigating circumstance. Additionally, the respondents would be required to provide that expert witness at their own expense.

Potere points out that California is the only state that requires disabled respondents to hire an expert witness to prove that they have a disability. Every other state either follows the ABA Standard 9.32(i), which requires only “medical evidence,” or has no evidentiary requirement at all.

Potere argues that Standard 1.6(d)’s heightened evidentiary burden for disabled respondents violates their constitutional right to due process and equal protection, along with their right to be free from discrimination based on their disability pursuant to the American with Disabilities Act.

Potere brought the lawsuit on behalf of himself and those similarly situated. He asked for the court to issue a declaratory judgment that Standard 1.6(d) violates the due process and equal protection clauses of the U.S. Constitution and violates Title II of the Americans with Disabilities Act. Potere also asked the court to permanently enjoin The State Bar of California for using or enforcing Standard 1.6(d) as it is currently written.

Supreme Court Building in DC

Federal Advisory Committee Considers Significant Change to Rule 702

After the Supreme Court’s Daubert decision, judges may only admit expert testimony that is based on a reasonable methodology. A question that divides federal courts is whether expert opinions should be admitted if a jury could reasonably regard the expert’s methodology as reasonable even if the judge doesn’t. A federal advisory committee may soon propose a change in the rule that resolves that question in favor of judges rather than juries.

A Brief History of Rule 702

Rule 702 of the Federal Rules of Evidence governs the admissibility of expert testimony. The first version of the rule, adopted with the other Rules of Evidence in 1973, allowed qualified witnesses to express expert opinions if their “scientific, technical, or other specialized knowledge” would “assist the trier of fact to understand the evidence or to determine a fact in issue.” The rule made the expert’s qualifications a matter of “knowledge, skill, experience, training, or education.”

The rule said nothing about the judge’s role in determining whether the expert’s opinions were reliable. When Rule 702 was adopted, federal courts followed the Frye standard of admissibility. Using that standard, courts admitted expert opinions based on scientific techniques that were, in the judge’s opinion, “generally accepted” as reliable in the relevant scientific community.

The Frye standard prevented juries from hearing opinions that were based on new or novel theories that, while reliable, were not yet generally accepted. The standard therefore kept juries from hearing reliable evidence that might help them decide the case. At the same time, the Frye standard allowed juries to hear unreliable testimony because courts had been ruling for years that the testimony was “generally accepted” as reliable. The Frye standard was particularly harmful in criminal cases. Unreliable forensic evidence, including bite mark and hair comparisons, has contributed to the widespread phenomenon of wrongful convictions.

In 1993, the Supreme Court purported to cure the deficiencies of the Frye standard by creating a new rule. The Daubert standard (named after the case in which it was adopted) expands the judge’s “gatekeeper” role in deciding whether evidence is sufficiently reliable to be admitted.

The Daubert decision held that Rule 702 was inconsistent with the Frye standard. The Court noted that the drafting history of Rule 702 did not mention Frye and concluded that “a rigid ‘general acceptance’ requirement would be at odds with the ‘liberal thrust’ of the Federal Rules and their ‘general approach of relaxing the traditional barriers to opinion testimony’.”

The Daubert court jettisoned the Frye standard. To fill the void, it created a new rule that, as interpreted by some judges, is incompatible with the “liberal thrust” of Rule 702 and its goal of relaxing barriers to expert testimony.

The Daubert standard broadened the admissibility of expert opinions by making reliability, rather than general acceptance, the dominant consideration in the judge’s analysis. At the same time, the standard narrowed the admissibility of expert opinions by requiring the judge to exclude expert opinions unless they are based on a reliable methodology that the expert applied to adequate facts in a reliable way.

Rule 702 was amended in 2000 to reflect the Daubert holding. The rule was amended again in 2011 to clarify its language. The current rule states:

A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:

(a) The expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;

(b) The testimony is based on sufficient facts or data;

(c) The testimony is the product of reliable principles and methods; and

(d) The expert has reliably applied the principles and methods to the facts of the case.

Criticisms of Current Rule

The Daubert standard as embodied in the current version of Rule 702 has been criticized for its lack of clarity. Some judges view the Daubert standard as expanding the admissibility of expert testimony. Those judges typically leave it to juries to decide whether to accept or reject expert opinions that could reasonably be regarded as reliable. Other judges view their role as determining reliability according to their own strenuous standards without regard to how a jury might view the evidence.

Critics who believe judges too often allow juries to evaluate expert testimony are advocating another change in the rule. Echoing the views of the insurance defense industry, those critics claim that judges are failing to exercise their role as the “gatekeepers” of reliability.

The critics cite anecdotal evidence to create the illusion of a widespread problem. One journalist, relying on his distant memory of an expert witness who gave allegedly inconsistent testimony in two different cases, recently wrote that he “wouldn’t believe a word from an ‘expert’ witness.” The journalist did not seem to appreciate that experts base opinions on facts and that different facts in different cases lead to different opinions.

Unfortunately, the reporter’s perspective advances the strange but popular belief that expert opinions do not reflect objective reality but are simply what the expert chooses to regard as true. That belief is encouraged by political assertions that objective facts are “fake news” and by attacks upon scientific experts who warn the public about dangers (such as global warming) that politicians would prefer to ignore. Attacks on expertise have given birth to a subculture that rejects expert opinions in favor of biased opinions on the ground that an unsupported opinion is just as valid as one based on facts, experience, education, and sound reasoning.

Some critics have suggested that judges should restrict expert testimony in civil cases to prevent “runaway juries” from deciding cases based on emotions rather than facts. Since those critics rarely express concern that juries convict innocent defendants because of emotional reactions to evidence of victimization, the critics seem to be more interested in protecting businesses from the consequences of their carelessness or misconduct than in protecting the right of litigants to have disputed facts resolved by juries.

Critics who complain that judges are inadequate gatekeepers often represent or work for industries that are sued for harming the public with dangerous products or environmental hazards. Those critics tend to brand experts as unscrupulous, but only when they testify for plaintiffs. The critics argue that Daubert was meant to limit expert testimony offered by plaintiffs despite the Supreme Court’s recognition that “relaxing the traditional barriers to opinion testimony” was the very purpose of Rule 702.

Proposed Revision of Rule 702

A recent report from the Advisory Committee suggests a change in Rule 702 that the committee may ask the Supreme Court to adopt. The change results from the concern that “in many cases expert testimony is permitted because the judge thinks that a reasonable jury could find the methods are reliable.” The Committee appeared to be horrified by the thought that jurors are just as capable of evaluating the reliability of evidence as judges. A who allows jurors to evaluate testimony that they could reasonably view as reliable does so because the judge respects the jury’s role in evaluating evidence.

Judges, after all, are not scientists. There is no reason to believe that judges are any more capable than jurors of understanding and evaluating expert testimony. As a Fourth Circuit decision reminded us in 1934, “Questions of fact are questions for the jury; and they do not become questions for the court merely because their solution may require scientific knowledge or expert opinion.”

Some members of the committee, however, have concluded that only judges have the wisdom to decide whether an expert’s methods are reliable. Their argument that judges should substitute their view of an expert’s reliability for a reasonable view that a jury might take is consistent with a disturbing trend to remove cases from juries — a trend that some scholars decry as reflecting a pro-business bias. Their apparent goal is to change gatekeepers into gate closers.

The report proposes “an amendment to Rule 702 that would clarify that expert testimony should not be permitted unless the judge finds by a preponderance of the evidence that each of the prerequisites are met.” In other words, even if a jury could reasonably find that an expert’s methodology was reliable, a judge who feels otherwise can prevent the jury from making that determination. The proposal represents one more effort to chip away at the American ideal that juries, not judges, should decide cases.

As Judge Kathleen O’Malley recently wrote, the jury is a vital tool in a deeply divided country, a tool that “protects all of us from overreach by the other two branches of government.” In Judge O’Malley’s view, “If two minds are better than one, nine or twelve are better still.” Judge O’Malley is confident that jurors acting collectively are just as capable as judges of evaluating expert testimony, and that it is arrogant for judges to suggest otherwise.

The advisory committee meets again in June 2021. Whether and when the committee will decide to propose a revision of Rule 702 is unclear. Equally uncertain is whether the Supreme Court would agree that it is wise to undermine expert testimony by giving judges more power to prevent juries from considering expert opinions that jurors might reasonably regard as being based on a reasonable methodology.

Policeman standing with crossed arms

Colorado Supreme Court Allows Police Officers to Testify About Body Language Without Expert Designation

The Colorado Supreme Court has ruled that police officers may testify about how they interpret body language without first being designated as expert witnesses.

The Non-Verbal Response

A fifteen-year-old student was sent to the school counselor after a teacher expressed concern that the student appeared ill.  During his meeting with the counselor, the student explained that he had attended a concert the night before with his thirty-five-year-old stepsister, Justine Murphy, and that he had used methamphetamine with her before the concert.

The student was admitted to a local hospital for evaluation and recovery. The school resource officer, Deputy Mark Johnson, interviewed the student while his father was present. During the interview, Deputy Johnson asked the student where he got the methamphetamine and if he had gotten it from his stepsister. Deputy Johnson later testified that instead of responding, the student’s body language changed, instead of looking directly at him, he looked down and away. The deputy took the student’s nonverbal response to mean that he didn’t want to answer because the answer was yes, so he asked a follow-up question, “Did she just give it to you or did she sell it to you?” The student responded that “She sold it to me.”

Murphy was charged with distributing a controlled substance and contributing to the delinquency of a minor.

Expert Designation Issue

Prior to trial, defense counsel objected to Deputy Johnson testifying about the inference he had drawn from the student’s non-verbal response. Defense counsel argued that the deputy should have been first qualified as an expert witness.

The trial court overruled the objection, finding that Deputy Johnson’s testimony constituted lay opinion testimony because he had observed the student’s body language and had a rational basis for forming an opinion about the body language.  A jury found Murphy guilty of distributing methamphetamine and contributing to the delinquency of a minor.

Murphy appealed and the court of appeals reversed, ruling that Deputy Johnson’s testimony was improper lay testimony “because it provided more than an opinion or inference rationally based on his perception.” Instead, the court concluded that Johnson’s testimony was based upon his training and experience. It could just as easily be said that Johnson’s testimony was improper because it was speculative.

The state appealed to the Colorado Supreme Court. The Colorado Supreme Court granted certiorari. The court clarified that lay witnesses are generally confined to stating facts, as opposed to providing opinions, inferences, or conclusions. Lay witnesses may provide opinion testimony where it is “(a) rationally based on the perception of the witness, (b) helpful to a clear understanding of the witness’[s] testimony or the determination of a fact in issue, and (c) not based on scientific, technical, or other specialized knowledge within the scope of Rule 702.”  In contrast, expert opinion testimony is “scientific, technical, or other specialized knowledge [that] will assist the trier of fact to understand the evidence or to determine a fact in issue” and requires an expert’s “knowledge, skill, experience, training, or education” to provide the requisite foundation for that specialized knowledge.

The court determined that the trial court properly admitted Deputy Johnson’s opinion as lay testimony. It concluded that any lay person could have come to the same conclusions as the officer. The court wrote, “Anyone who has interacted with children, for example, could infer that a child who looks away or avoids eye contact when confronted about their misbehavior (‘Did you take the cookie?’ ‘Did you hit your brother?’) may be tacitly acknowledging that misbehavior.”

Of course, the same body language may signal that the child feels intimidated by the officer and doesn’t want to interact further for that reason. The officer is not a mind-reader. It should be up to the jury, not the officer, to draw inferences based on the officer’s testimony about what the officer saw.

By reversing the Colorado Court of Appeals ruling, the state supreme court reinstated Murphy’s conviction and eight-year prison sentence.

Expert Witness

Expert Witness Report Rule Relaxed in Expedited Litigation

A Virginia district court has relaxed the expert witness report rule in the case of expedited litigation.

The Abduction

Bryce Gerald Randall Nowlan and Nina Lynn Nowlan were married and had a daughter, “AEN.” Bryce Nowlan is a Canadian citizen who resides in Canada. Nina Nowlan is an American citizen who currently resides in Virginia. Bryce Nowlan alleges that Nina Nowlan wrongfully took their daughter from his custody in Canada to Virginia.

Bryce Nowlan filed a petition for AEN’s return to Canada under The Convention on the Civil Aspects of International Child Abduction (the Hague Convention) and the International Child Abduction Remedies Act. He also filed a motion to expedite the proceedings under the Hague Convention.

Court Proceedings

The parties submitted a proposed scheduling order. The parties agreed on all matters with one exception. Bryce Nowlan proposed that both parties should provide “full and complete expert disclosures as required by Rule 26(a)(2)(A)-(C) of the Federal Rules of Civil Procedure” and “full and complete rebuttal expert disclosures, which shall also comply with Rule 26(a)(2)(A)-(C). Nina Nowlan objected to “importing the strict disclosure requirements of Rule 26, particularly since this matter is proceeding on an expedited basis.” Rule 26 requires that a witness prepare and sign a detailed report at the expense of the disclosing party. Since Nina Nowlan is indigent, she requested that the court instead require counsel for each party to provide summaries of each expert’s anticipated opinions.

The court granted Nina Nowlan’s request and required each party to provide “detailed written summaries of their experts’ opinions and conclusions.” The court noted that it was “cognizant of the onerous burden imposed by Rule 26 regarding expert witness disclosures and Ms. Nowlan’s objection to complying with the strictures of the rule due to both time and expense. The court agrees and notes that this, at bottom, is a summary proceeding with expedited deadlines, modified procedures, and relaxed standards for the admissibility of evidence. Given these unique factors, respondent’s objection is persuasive. The court will grant the parties latitude during the cross examination of any expert witness as necessary to account for any expert report that is less than fulsome than a standard Rule 26 report.”

Bryce Nowlan objected to the “truncating” of expert-disclosure obligations under Rule 26(a)(2)(B) in light of Nina Nowlan’s claims that he had sexually abused AEN. His objection stated that the court’s order did not provide him with the opportunity that he would have had under Rule 26 to note any Daubert challenges or move in limine to exclude a proposed expert in advance of trial.

Court Ruling

The court noted that district courts are “afforded substantial discretion in managing discovery.” It also noted that Rule 26(a)(2)(B) contemplated deviations from the typical requirements for expert witnesses’ written reports by including the language “unless otherwise stipulated or ordered by the court.”

The court noted that its order still required the parties to produce “detailed, written summaries” and that it had granted the parties “latitude during the cross examination of any expert witness as necessary.”

The court was satisfied that the parties were able to adequately prepare for the bench trial and bring any purported insufficiencies or shortcomings of the other party’s expert witnesses at trial and overruled Bryce Nowlan’s objections.

Criminal Forensics, word cloud concept 11

Does the CSI Effect Hurt Prosecutors Who Don’t Rely on Expert Witnesses?

It has become an urban legend, at least among prosecutors, that jurors have been conditioned by the CSI franchise (CSI: Crime Scene Investigation, CSI: Miami, CSI: NY, and CSI: Cyber) to expect guilt to be proved beyond doubt by forensic evidence. Prosecutors fear that they will lose cases if they try to prove guilt the old-fashioned way: with confessions, eyewitness testimony, or inferences based on motive and opportunity.

It isn’t unreasonable for jurors to expect prosecutors to rely on expert witnesses when they can. After all, the Constitution requires guilt to be prove beyond a reasonable doubt. If fresh blood found at the scene of the crime isn’t analyzed for DNA, a jury might reasonably wonder why the government didn’t do everything in its power to determine whether the blood belonged to a criminal suspect.

Still, forensic evidence isn’t available in every case. Sometimes there’s no physical evidence to analyze. In other cases, budgets may be inadequate to fund an expert. When those circumstances occur, does a case become unwinnable?

Concerns About the CSI Effect

A state’s attorney in McLean County, Illinois recently warned readers of a Central Illinois newspaper that CSI is not realistic. When he questions potential jurors, he asks them whether they “expect to see satellite imagery and laser grid analysis.” His questions are intended to remind jurors that high tech evidence isn’t needed or available in every case.

Whether the CSI effect actually exists is open to debate. A 2006 survey asked participants whether they would expect to see various kinds of evidence in seven different cases ranging from murder to theft. Participants were asked, for example, whether they would expect to see “eyewitness evidence,” “some kind of scientific evidence,” “fingerprint evidence,” and “DNA evidence.”

The survey found that 46{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} of participants expected to see some kind of scientific evidence in every criminal case, 32{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} expected to see ballistic evidence in every criminal case, and 22{d61575bddc780c1d4ab39ab904bf25755f3b8d1434703a303cf443ba00f43fa4} expected to see DNA evidence in every criminal case. Since ballistic evidence pertains to firearms and since most crimes are committed without a firearm, the survey results might indicate that participants were not given sufficient information to make rational responses.

The survey also found that participants who watched a CSI show regularly were more likely to demand scientific evidence in every case than participants who rarely or never watched CSI. Those results were dutifully reported by the Central Illinois journalist who fretted about the impact of CSI on jurors.

The journalist neglected to report the survey’s central finding: Participants were not more likely to acquit a defendant simply because guilt was not supported by expert evidence. A recent article in the ABA Journal notes that the 2006 survey was followed by an urban survey in 2008-09 that found even less reason to believe that a CSI effect results in unwarranted acquittals. A judge who helped design the survey attributed worries about the CSI effect to “grumbling prosecutors.”

While survey participants said that the absence of scientific evidence would not make them more inclined to acquit, they were more likely to doubt guilt in the absence of eyewitness testimony. Ironically, eyewitness testimony is among the least reliable forms of evidence in a criminal prosecution. The defense lawyer in a case that turns on eyewitness identification should give automatic consideration to the need for an expert witness who can explain why identifications are so often mistaken.

Should Jurors Be Cautioned About the CSI Effect?

How participants respond to hypothetical questions on a survey is probably a poor measure of how they will judge the evidence in an actual trial. It makes little sense to think that jurors will worry about the absence of ballistic evidence in a case that does not involve a gun. No judge would allow a defense attorney to question the absence of evidence that isn’t relevant to the case.

The judge who was interviewed in the ABA Journal article argued that prosecutors might actually trigger a CSI effect by asking potential jurors whether they expect guilt to be proved by scientific evidence. If potential jurors aren’t thinking about scientific evidence before the prosecutor talked to them, they may wonder about its absence when the prosecutor calls attention to it.

In some cases, however, a defense lawyer’s comments about the prosecution’s failure to present forensic evidence is legitimate. The Journal article reports a Maryland case in which a criminal defense lawyer called the jury’s attention to the absence of scientific evidence to prove that the defendant had handled a screwdriver or tape found at the scene of the burglary.  No expert witness testified about fingerprints or DNA samples that one might expect to find on that evidence.

It is commonplace for lawyers to argue that a police investigation was incomplete and that the failure to make a diligent search for evidence creates reasonable doubt. The trial judge in the Maryland case nevertheless instructed the jury that ““there is no legal requirement that the state utilize any specific investigative technique or scientific test to prove its case.” That’s true, but there is a legal requirement that prosecutors prove guilt beyond a reasonable doubt.

An appellate court found that the instruction improperly undermined the defense theory that the absence of scientific evidence contributed to reasonable doubt. The defense lawyer did not argue that the prosecution had an obligation to present expert evidence. Rather, the lawyer argued that the prosecution had the ability to ask experts to analyze the evidence and that its failure to conduct a complete investigation of the evidence created a reasonable doubt about the defendant’s guilt. That argument did not warrant a jury instruction regarding the prosecution’s failure to produce scientific evidence.

Similar instructions have come to be known as “anti-CSI instructions.” Prosecutors argue that the instructions are needed to overcome the CSI effect. Since there is little evidence that the CSI effect actually exists, fair judges keep their thumb off the scale and avoid giving instructions that seem to excuse a prosecutor’s failure to introduce expert evidence when a case seems to call for it.


A white cop

Seventh Circuit Permits Police Officer to Testify as Drug Jargon Expert

The odds of admitting expert testimony are stacked against defendants in criminal cases. An analysis of federal criminal prosecutions found that judges almost always admit expert testimony offered by prosecutors but usually disallow the expert testimony of defense experts.

Prosecutors commonly rely on police officers to provide expert testimony. While the officers are not allowed to testify that a defendant is guilty (an issue that only the jury can decide), they are often allowed to give “ultimate issue” testimony that invites the jury to find guilt. To a jury, there is little difference between testifying that “In my opinion, the defendant sold drugs” and testifying that “In my expert opinion, all of the evidence is consistent with the defendant selling drugs.”

Federal courts have been criticized for their lax application of the Daubert standard to police officer testimony. Other experts are required to demonstrate that they formed opinions through the reliable application of a sound methodology to sufficient facts. Police officers are often allowed to couch any opinion as an expert opinion simply by claiming that the opinion is based on their experience in law enforcement.

A common example of the lax application of Daubert involves “expert” testimony about the meaning of “drug jargon.” A recent decision of the U.S. Court of Appeals for the Seventh Circuit determined that police officers can offer expert opinions about the hidden meaning of ordinary words that a defendant uses in text messages.

Facts of the Case

Maurice Gardner was the passenger in a car that was stopped by police officers in Evansville, Illinois. For reasons that the appellate opinion does not explain, the officers searched the vehicle. They found bags containing six grams of methamphetamine, digital scales, and a loaded firearm. Officers testified that they asked Gardner why he was in the vehicle and Gardner admitted that he was trying to sell drugs.

Given those facts, the government had a slam dunk case on the drug charges. It nevertheless bolstered its evidence by calling Evansville Police Officer Cliff Simpson as an “expert in narcotics distribution.” Since the jury was just as capable of interpreting the evidence as Simpson, this was not the kind of case in which the testimony of an “expert in narcotics distribution” would normally be admissible. The prosecution, however, wanted Simpson to “translate” text messages on Gardner’s phone that the prosecution claimed were “coded.”

Simpson claimed expertise because he had “interpreted” text messages and phone calls in more than a dozen wiretap investigations. The prosecution apparently offered no evidence that Simpson had interpreted the communications accurately.

Expert Opinions

Gardner received a text message that said “she will pay 245 for it.” Simpson testified that the message meant “someone would pay $245 for methamphetamine.” Since neither “245” nor “it” are drug jargon, it is difficult to understand why the judge felt that an expert was needed to decode the message. Whether “it” referred to methamphetamine was an inference that the jury could draw without Simpson’s guiding hand.

The same is true of Gardner’s reply: “I can do one for 250 and dat’s all.”  The phrase “do one” likely means “sell one” in context, but there’s nothing coded about that language. Simpson’s testimony that Gardner meant that he was willing to sell a quantity of the drug for $250 hardly requires an expert interpretation.

Simpson might have relied on expertise when he testified that 3 grams of methamphetamine would retail for $250, but the message did not say “I can sell three” or “I can sell an eight ball” (jargon that describes an eighth of an ounce, or about 3.5 grams). The jury was just as capable as Simpson of inferring that “one” referred to an unspecified drug quantity.

Finally, Gardner texted, “I ain’t got dat kind of deal rite now. I’m grinding dis out.” Simpson believed “dat kind of deal” referred to a lower price, an obvious conclusion that requires no expertise.

Simpson also testified that “grinding dis out” meant that Gardner was not selling large amounts but was breaking down his supply to sell in smaller amounts. Perhaps that’s true. Or perhaps Gardner was saying that he was just trying to get through the daily grind of his day. It is not at all clear that Simpson’s opinion about the meaning of Gardner’s words was grounded in expertise rather than assumptions.

Daubert Challenge Rejected

Perhaps the common practice of street dealers to make more money by risking multiple smaller sales rather than giving a quantity discount for a larger sale is not a practice that juries would understand without expert testimony. But Simpson did not explain how street dealers work. He simply offered a personal opinion of what “grinding dis out” meant. A reasonable expert methodology would require the expert to study the jargon used by drug dealers and to identify other instances in which “grinding dis out” meant “selling smaller quantities.” Nothing in the appellate opinion suggests that Gardner based his opinion on a reasonable methodology.

The appellate court nevertheless concluded that a different standard of reliability applies when an expert witness is a police officer. The expert officer does not need to employ a reasonable methodology to arrive at a reliable opinion. It is enough for the officer to base an opinion on the officer’s experience. The court held that “the reliability of the expert’s methods may reasonably be inferred from the expert’s background.”

Experts who testify about harms caused by dangerous drugs and toxic exposures need to rely on reasonable methodologies, no matter how “vast” their experience might be. Why is the Daubert rule different for the police? The Seventh Circuit made no attempt to justify its application of a different standard that benefits the prosecution in criminal cases. A cynic might conclude that the court simply wanted to make it easier for the government to win criminal cases and abandoned doctrinal consistency to advance that goal.

The court also rejected the argument that “Simpson interpreted innocuous, everyday words that need not be decoded by an expert.” According to the Seventh Circuit, words that might “seem entirely innocuous” to ordinary jurors can be recognized as “drug jargon” by police officers. Perhaps there are instances where that might be true, but nothing in the phrase “I can do one for 250” even remotely qualifies as coded drug jargon. What Gardner meant by “one” is an inference to be drawn from all the facts. It is not a “coded” word that only an expert can interpret.

In the end, the case against Gardner was so strong that Simpson’s testimony likely had no impact on the verdict. The court of appeals covered itself by noting that the district court’s decision to admit the testimony would have been a harmless error even if the appellate court had found the decision to be erroneous. The decision nevertheless provides further support for the sad conclusion that “the Daubert revolution, aimed at upgrading the quality of expert evidence, has had surprisingly little impact in the criminal courts.”