Category Archives: Research & Trends


Experts Question Reliability of Forensic Video Evidence

The need for criminal defense attorneys to hire independent expert witnesses has never been more clear, as the reliability of testimony given by expert witnesses who work for the police has increasingly been called into question. Unfortunately, the importance of an independent expert witness to a fair trial isn’t always apparent to defense attorneys or to judges.

Two cases involving robberies of 7-Eleven stores illustrate the importance of retaining a forensic video expert when a criminal accusation is supported by video evidence. In both cases, the defendants were convicted of robbery based on expert testimony that the defendants were the same height as the robber shown on surveillance camera footage. In both cases, independent forensic video experts hired after the defendants were sentenced concluded that the surveillance videos proved the defendants’ innocence.

George Powell III

George Powell III was charged with robbing a 7-Eleven store in Killeen, Texas in 2008. A surveillance video showed a man wearing sunglasses and a baseball cap pointing a gun at the store clerk. The video was broadcast on the news and the police arrested Powell in response to a tip from a television viewer.

At the time of the robbery, the clerk estimated that the robber was 5 feet 6 inches tall. Shown a photo array of faces, she picked Powell’s photograph. She was not aware, however, that Powell is 6 feet 3 inches tall. Other clerks were less confident that Powell was the robber.

It isn’t uncommon for eyewitnesses to be mistaken when they are shown photographs rather than seeing an in-person lineup. The method used to obtain the clerk’s identification of Powell is so unreliable that it was later banned in Texas courts.

To deal with the height discrepancy, the prosecution called Michael Knox as an expert witness. Knox, a retired police officer, testified that he used the science of photogrammetry to determine that the robber in the video was more than 6 feet tall. Knox had no training in photogrammetry and had never before attempted to determine a suspect’s height based on a video image. Powell was nevertheless convicted on the strength of that evidence, coupled with the testimony of a Texas jailhouse informant that was later recanted.

Powell’s family eventually hired two experts who examined the video and determined that the robber was about 5 feet 7 inches tall. The Texas Science Commission then hired Grant Fredericks, who taught video analysis at the FBI National Academy. Fredericks determined that the robber was somewhere between 5 feet 6 inches and 5 feet 9 inches tall. All three expert opinions excluded Powell as a suspect. All three experts agreed that Knox did not follow professional standards in forming his opinion about the robber’s height.

Powell’s defense team has filed a motion challenging the conviction. A district judge will consider the evidence, including the new expert evidence, and make recommendations to the Texas Court of Criminal Appeals as to whether Powell should be granted a new trial.

Michael Hutchinson

A clerk who was robbed at gunpoint at a 7-Eleven in Milpitas, California identified Michael Hutchinson as the robber. The identification was problematic because the robber was wearing a mask. Hutchinson was nevertheless convicted in a 1998 trial.

Hutchinson’s appellate attorney asked the state appellate court to approve funds for a forensic video expert. The attorney told the court that an expert was needed to establish that Hutchinson was not the robber captured on tape by the store’s surveillance camera. Deciding that an expert was unnecessary, the court affirmed Hutchinson’s conviction.

After taking an interest in Hutchinson’s case, the Mercury News hired a forensic video expert to examine the surveillance video. The expert concluded that the robber was much shorter than Hutchinson.

Hutchinson then brought his case before a federal judge. Relying in part on the forensic video expert’s opinion, the judge ruled that Hutchinson’s attorney failed to protect his client’s right to a fair trial. The judge concluded that the attorney should have recognized the need for an expert analysis of the videotape.

The judge’s decision that Hutchinson was entitled to a new trial was affirmed on appeal. The federal appellate court chastised the state courts for failing to fund the hiring of a necessary expert.

Forensic Video Analysis

Forensic video analysis has become increasingly important as more businesses, government buildings, and private homes install video cameras that capture the images of criminal suspects. The April 2016 report by the Texas Forensic Science Commission, prepared in response to Powell’s complaint, recognizes the legitimacy of photogrammetry. At the same time, the fact that different experts arrive at different height estimates when examining the same video “gave the Commission pause and raised concerns as to the state of forensic video analysis.”

The Commission noted that “the subjectivity involved in the different approaches to making a height determination raises questions about inter-analyst reliability within the discipline.” The absence of known error rates, the failure of analysts to standardize an analytical method, and the presence of confirmation bias (where the analyst knows the suspect’s height before undertaking the analysis) all raise questions about whether expert forensic video analysis should be admissible against a defendant in a criminal trial.

Lessons Learned

The cases of Powell and Hutchinson spotlight the importance of independent experts. In both cases, the defense attorney should have retained a forensic video expert to determine whether the robber was the same height as the defendant.

Blindly putting faith in the ability of the prosecution’s expert is a mistake, since experts who work for the police too often see themselves as advocates for the prosecution, not as advocates for the truth. At the very least, a criminal defense attorney who is faced with a prosecution expert in forensic video analysis should read and understand the concerns raised by the Texas Forensic Science Commission.

At the same time, too many judges believe that experts should only testify for the prosecution, not the defense. The Texas court that denied Powell’s request for funding to hire a forensic video expert assumed that an independent expert would add nothing of value to the proof. The court’s conclusion that an independent expert would not have been helpful is belied by recent revelations that forensic video experts employed by police agencies, when left unchallenged by independent experts, contribute to wrongful convictions.

North Carolina

N.C. Supreme Court Adopts Daubert, Excludes Use of Force Expert

Charles McGrady was convicted in North Carolina of murdering his cousin, James Shore Jr. McGrady admitted that he shot Shore but claimed that he acted in self-defense. The trial court denied his request to call a “use of force” expert in his defense.

On appeal, the state’s highest court decided that the federal Daubert standard of expert witness admissibility now applies in North Carolina. Applying that exacting standard, it affirmed the lower court’s exclusion of the expert testimony.

Facts of the Case

McGrady and Shore lived across from each other in a trailer park. They had a long history of combative behavior.

McGrady testified that the night before the shooting, Shore threatened to kill him. The next day, McGrady drove his golf cart to his mailbox. His son, seated next to him, was armed with an assault rifle. McGrady was carrying a 9-millimeter handgun.

As McGrady was driving back to his trailer, he saw Shore shouting and moving toward him. McGrady activated a tape recorder that captured much of the argument between the two men. McGrady accused Shore of threatening to kill him. Shore accused McGrady of shining a spotlight on him the previous night. Another witness testified that it was not a spotlight but the laser sight of an assault rifle that McGrady pointed at his cousin.

The men exchanged a variety of threats. According to McGrady’s son, Shore approached the golf cart and began to shake it. McGrady testified that Shore also threatened them with a knife.

McGrady asked his son to hand him the assault rifle “to defuse the situation,” an act that prompted Shore to reach for the rifle. Whether Shore actually grabbed the rifle was disputed by the witnesses.

McGrady testified that Shore pointed the rifle at his son’s head. McGrady then shot Shore with his handgun. McGrady fired seven shots, four of which struck Shore.

McGrady argued that he acted in self-defense and in defense of his son. To bolster that defense, he wanted to call Dave Cloutier as an expert in “the science of the use of force.” The trial court denied that request and McGrady was convicted of murder.

Admissibility of Expert Testimony in North Carolina

In 2011, the North Carolina General Assembly amended Rule 702(a) of North Carolina’s Rules of Evidence. The version that the legislature adopted tracked the language of the federal rule governing the admissibility of expert testimony. The federal rule is commonly known as the Daubert standard, based on a United States Supreme Court case that defined the trial court’s responsibility in applying the rule.

In 2004, the North Carolina Supreme Court had concluded that “North Carolina is not, nor has it ever been, a Daubert jurisdiction.” The Court was concerned that “the ‘exacting standards of reliability’ demanded by the federal approach” required judges to invade the province of the jury by evaluating “the substantive merits of the scientific or technical theories undergirding an expert’s opinion.”

In McGrady’s appeal, the Court overruled that precedent and held that the “the meaning of North Carolina’s Rule 702(a) now mirrors that of the amended federal rule.” According to the Court, “the General Assembly has made it clear that North Carolina is now a Daubert state.”

The Court concluded that federal precedent construing the Daubert standard should guide North Carolina cases. Of course, as ExpertPages has often noted, federal courts have adopted varying interpretations of the federal rule. Some interpretations are more liberal and others are more restrictive in defining the judge’s role as the “gatekeeper” of expert evidence.

North Carolina had a fairly liberal standard for the admission of expert evidence before the legislature adopted the Daubert standard. The Court concluded that its prior cases will continue to guide judges, but only to the extent that they are not inconsistent with Daubert. For the most part, cases that decided whether expert testimony would be helpful to the jury and whether the expert was qualified to testify will still be good law in North Carolina. The key difference between the old and new standards is that a judge’s assessment of whether expert testimony is reliable will be more rigorous than it was in the past.

McGrady’s Expert

McGrady expected his use of force expert to provide three opinions:

  • the “pre-attack cues” and “use of force variables” present in the interaction between McGrady and Shore made McGrady’s perception of an imminent, deadly assault reasonable and justified the use of deadly force;
  • McGrady’s actions and testimony are consistent with those of someone experiencing the sympathetic nervous system’s “fight or flight” response; and
  • the shots that hit Shore in the back can be explained by reaction times.

The North Carolina Supreme Court concluded that the trial judge did not abuse his discretion in disallowing that testimony. The appellate court agreed that McGrady’s perception of a likely assault was within the jury’s common knowledge and that an explanation of cues (such as threats and the display of a weapon) and variables (such as the age and size of the participants in the dispute) would not add anything to what jurors already understood.

The Court also agreed that Cloutier was not qualified to offer expert testimony about the stress responses of the sympathetic nervous system. Cloutier was not a doctor. He claimed to have “basic knowledge” of brain functioning based on taking college psychology courses, reading articles, and teaching police officers how to deal with stress responses. The Court concluded that while Cloutier “may have been eminently qualified to testify about standard police practices regarding the use of force, he was far less qualified to testify about the sympathetic nervous system.” Whether Cloutier was adequately qualified was a judgment call, and the trial court’s judgment was not so obviously wrong that the court could be said to have abused its discretion.

Finally, the appellate court agreed that Cloutier’s proposed testimony regarding reaction times was unreliable. Cloutier would have testified that a person can turn his body in less time than it takes to perceive a threat and fire a weapon, so Shore might have been facing McGrady when McGrady decided to shoot, but might have turned his back to McGrady before the shots were fired. The trial court thought the proposed testimony was unreliable because Cloutier based his opinion on reaction time studies, but admitted that factors such as clothing, injuries, and initial body position can affect reaction time. Those factors would seem to go to the weight a jury should give to Cloutier’s testimony rather than its reliability. In fact, use of force experts routinely testify about reaction times in cases where the police shoot a suspect in the back. The same standard presumably should apply to civilian defendants, but the Court concluded that the trial court did not abuse its discretion in deciding that Cloutier’s testimony was unreliable.

Implications for Expert Witnesses

In the end, the McGrady case is more important for its definitive ruling that North Carolina now follows the Daubert standard than for its application of that standard to Cloutier’s expert testimony. Other trial judges applying the same standard may have concluded that some parts of Cloutier’s testimony were admissible. In fact, use of force experts are common when police officers are on trial, so the McGrady decision should not be read as prohibiting use of force expert testimony in every case.

Cellphone, signals, wifi

Cellphone Experts Debate Validity of Location Evidence

In criminal cases across the country, FBI agents and local police detectives have testified as expert witnesses concerning the location of a suspect’s cellphone (and presumably the suspect) at the time a crime was committed. Whether law enforcement officers are qualified to give that testimony is a hotly contested question.

The Connecticut Supreme Court is the latest jurisdiction to consider whether cellphone location evidence is sufficiently reliable to be admitted at a criminal trial. The court’s decision will contribute to a continuing debate about the validity of the expert evidence, particularly when the expert witnesses are police officers with no background in engineering or telecommunications.

Eugene Edwards’ Appeal

Eugene Edwards Jr. was convicted of robbing Lieslotte Worysz, age 83, in Wethersfield, Connecticut. The prosecution argued that Edwards followed the woman home from the grocery store, entered her garage as she exited from her car, put his hand on her car door while brandishing a gun, stole her money and jewelry, and fled. The jury found Edwards guilty.

Edwards was also charged with committing a similar robbery of an elderly woman in Berlin, Connecticut three weeks earlier. The jury found Edwards not guilty of that crime.

Worysz described the robber as a black man between the ages of 35 and 40. She testified that the robber was holding a black gun. When the police showed her pictures of potential suspects, she said they all looked alike to her.

Worysz noticed a car behind her as she drove home. A surveillance video at the grocery store captured the car that Worysz described. Edwards was one of three people who, according to records of people with prior police contacts, owned a similar car. The police did not inspect the other cars. The car on the video had a broken brake light, but the brake lights on Edwards’ car were working.

Worysz said that the robber held her wallet and a garage door opener. A DNA analysis eliminated Edwards as a possible source of DNA found on the wallet and opener.

A fingerprint analyst could not match a partial print that was taken from Worysz’ car to Edwards, although a different analyst testified that the partial print came from Edwards’ left hand. Worysz testified that Edwards was holding the gun in his left hand. The defense argued that Edwards could not have opened the car door using a hand that was holding a gun. In any event, Connecticut law does not permit a conviction to be based on fingerprint evidence alone when the print was taken from a car that has been parked in a public place.

The police searched Edwards’ home and found a black BB gun with an orange tip. Worysz did not describe the gun she saw as having an orange tip. No jewelry or other crime proceeds were found in a search of Edwards’ car and residence about a week after the robbery.

Expert Testimony

Detective Christopher Morris testified as a cellphone expert based on his attendance at a three-day police training session in cellphone investigations. He opined that Edwards’ cellphone connected to towers near Worysz’ home and near the store where Worysz was shopping on the day of the robbery. He also testified that cellphones connect to the nearest tower, although he acknowledged that facts such as weather, network congestion, network maintenance, topology and foliage can all affect the cellphone’s connection to a particular tower.

The prosecution called a Verizon employee to authenticate the records upon which Morris relied, but the trial court ruled that the employee was not an engineer and was not qualified to offer any opinion as to whether Edwards’ phone would have connected to the nearest tower. However, the court held that Morris was qualified as a “police expert” to testify about cellphone locations based on his training and experience.

Morris gave no testimony about peer-reviewed studies that validated his methodology. He gave no testimony about error rates that occur when his methodology is used to determine cellphone locations. The prosecution offered no evidence that Morris was trained by scientists or engineers or that his training was based on accepted scientific principles. The Connecticut Supreme Court agreed to decide whether a police witness who is not an engineer and has no scientific training other than “police training” is qualified to give reliable testimony about cellphone locations.

Controversial Evidence

Connecticut joins a growing number of jurisdictions that are tackling the use of law enforcement officers to testify as expert witnesses regarding cellphone tracking. Some independent experts, like Michael Cherry, say that their testimony is based on “junk science.”

Cherry notes that police officers “tend to confuse the location of the cellphone with the location of the cell tower.” According to Cherry:

People like to say that the phone goes to the nearest tower. It goes to the clearest tower within range, not always the closest tower. You could be sitting on your living room couch and you could make four phone calls and each call would use a different tower.

Getting that point across to jurors may require defense attorneys to retain the services of independent experts. The initial question confronting courts, however, is whether police officers who have no background in science are able to give reliable testimony about cellphone locations based on brief training sessions that are taught by other police officers who have no background in science.

Judicial Decisions

As ExpertPages has noted in the past, different trial courts have reached different conclusions about the admissibility of expert testimony concerning cellphone locations. In Maryland, Adnan Syed was recently granted a new trial because his lawyer failed to cross-examine a state’s expert witness about the reliability of cell tower data that allegedly placed him near the site of the victim’s burial.

Lisa Marie Roberts, convicted of murder in Oregon, was also granted a new trial based on her attorney’s failure to challenge questionable expert cellphone location evidence. A judge in that case ruled that there were serious doubts about Roberts’ guilt.

A federal judge in Chicago refused to allow an FBI agent to testify about a cellphone location in a kidnapping case. The court concluded that the agent’s “chosen methodology has received no scrutiny outside the law enforcement community” and that the reliability of that methodology had therefore not been established.

Other courts have routinely admitted cellphone tracking evidence, perhaps because defense lawyers do not realize that they have grounds for challenging its admissibility. Evidence professor Edward J. Imwinkelried encourages lawyers to use their own experts to challenge law enforcement agents who claim that they can determine the location of a cellphone using cellphone tower records.


Can a Computer Program Be an Expert Witness?

When DNA testing is too complex for police crime labs, the labs sometimes outsource their testing to a company like Cybergenetics. Most crime labs can handle DNA testing when the DNA to be analyzed comes from one person, but the process is much more complex when DNA from multiple sources has been mixed together.

Cybergenetics has developed a “probabilistic genotyping” software program called TrueAllele. The software uses algorithms that make judgments about how to separate DNA samples in order to create an individual DNA profile for each contributing source.

Computer Programs as Expert Witnesses

According to Cybergenetics, the TrueAllele program is superior to human analysts. Human experts, however, have the capacity to admit that they might be mistaken, particularly when an apparent flaw in their judgment is pointed out in court. The inability to convince a program that it reached an incorrect result is one reason why human experts might be preferable to computer software.

The use of a computer program to provide an expert opinion has sparked a controversy in the criminal justice system. While lab analysts can be cross-examined, it isn’t possible to cross-examine a computer program. In lieu of cross-examining TrueAllele, defense attorneys would like to have their own experts examine the program’s source code to determine whether the program might be flawed. Asserting that the source code is proprietary information, Cybergenetics refuses to release it, making it impossible to determine whether the program actually functions as intended.

The developers of TrueAllele claim that the program removes human bias from the testing process. But perhaps that claim reflects the bias of Cybergenetics, which makes money when outside agencies rely upon the program. Is TrueAllele really more accurate than human experts or is that a marketing claim?

Software Marketing

Cybergenetics offers to conduct a free preliminary analysis for police agencies. If the results show a probable DNA match, the agency can then decide to pay for a full analysis, complete with a report that can be offered as evidence at trial. That model provides an incentive to report a match — without one, Cybergenetics doesn’t get paid.

Cybergenetics’ primary competitor is STRmix, a program developed by a New Zealand-Australia collaboration and marketed by Nichevision in the United States. The FBI uses STRmix. David Balding, a professor of statistical genetics at the University of Melbourne, cites a study in which TrueAllele and STRmix were both used to examine a lab-created sample and returned “significantly different results.” That study suggests that one or both of the programs might be seriously flawed, but which one?

While both Cybergenetics and Nichevision claim that their programs are reliable, the studies that purport to demonstrate their reliability were conducted by the programmers, not by independent testing authorities. The recent White House PCAST report assessing the reliability of expert evidence noted that independent research is needed to verify those claims.

Cybergenetics argues that its internal test results should be sufficient, but Cybergenetics has an economic incentive to produce validation results that will help it sell its services. In the absence of independent testing, why should a court assume that probabilistic genotyping software is reliable?

Admissibility in Court

Courts that have considered whether to admit DNA testing results generated by computer programs have arrived at mixed results. A New York judge disallowed STRmix results in a high-profile case involving the strangulation death of 12-year-old Garrett J. Phillips. An earlier TrueAllele test in that case returned an inconclusive result. The judge decided that the prosecution failed to demonstrate the reliability of the STRmix program.

Other courts have decided to admit the evidence. For example, police officers in Onondaga County, New York stopped a car that was being operated without headlights. The car’s occupants fled into a park and shots were fired. Officers found a gun in the park, but they did not apprehend, and could not identify, any of the car’s occupants.

Police investigators determined that Frank Thomas owned the car. They had no other evidence that tied him to the gun. The local crime lab found the DNA of four to six people on the gun. Because the DNA was mixed, separating it and matching it to a particular suspect was beyond the crime lab’s ability.

The lab sent the samples to Cybergenetics. An analysis by the TrueAllele program computed a very high probability that DNA on the gun matched that of Thomas (or someone related to him). Believing he should not be required to take Cybergenetics’ word for the reliability of its program, Thomas’ lawyer asked for the program’s source code so that an expert could determine whether the program actually works. Cybergenetics refused to provide it and Thomas was convicted of reckless endangerment for firing the handgun. His case is on appeal.

Challenging Computer Software as an Expert Witness

A coding error in the STRmix program affected test results in at least 60 criminal prosecutions in Australia. Whether other errors exist in the source code can’t be determined without analyzing it, but the companies that developed TrueAllele and STRmix refuse to provide their source codes to defense attorneys.

Defense attorneys maintain that convicting defendants on the basis of “secret evidence” is inconsistent with constitutional values that emphasize the importance of cross-examination and disclosure of the basis for expert opinions. Both are fundamental to a fair trial, but it isn’t possible to cross-examine a computer program, and exposing flaws in the program isn’t possible without access to the source code.

Defense attorneys faced with DNA evidence that was produced by software rather than human experts can use their own expert witnesses to point out the inherent uncertainty of test results that cannot be validated by independent, unbiased scientists. Defense attorneys can also challenge the admissibility of evidence that depends upon an unproven methodology and that frustrates the constitutional right to confront a witness. Finally, defense attorneys can continue to demand to have the program’s source code analyzed by their own forensic computer experts.

Until appellate courts begin to recognize and address the problems caused by using software as an expert witness, the admission of probabilistic genotyping test results in a criminal trial will continue to raise serious concerns. As the Electronic Privacy Information Center contends, “Secrecy of the algorithms used to determine guilt or innocence undermines faith in the criminal justice system.”

Gavel and Stethoscope on Reflective Table

Ethical Challenges for Medical Expert Witnesses

An article entitled Ethical Challenges for the Medical Expert Witness in a recent issue of the AMA Journal of Ethics poses a hypothetical problem and asks expert medical witnesses to consider their ethical duties if they find themselves in a comparable situation.


The article poses the following hypothetical problem. A behavioral neurologist who occasionally testifies as an expert witness is asked to review the records pertaining to a personal injury victim who sustained a head injury. The victim was exiting from a parking lot when a truck collided with her vehicle. The victim’s attorney wants the neurologist to determine whether the collision was the most likely cause of the victim’s chronic headaches and cognitive dysfunction.

The medical records are ambiguous. Neither the police report nor the reports of the paramedics who arrived at the scene suggest that the victim was confused or disoriented. The records do not clearly state that the victim lost consciousness. A loss of consciousness and a period of confusion or disorientation are typical symptoms of a mild traumatic brain injury. The expert worries that if she testifies, she will need to reveal her concern that the documents do not clearly establish a loss of consciousness or confusion, facts that might undermine the belief that the victim suffered from a traumatic brain injury. She wonders if she should reveal her concerns to the attorney who hired her, or if she should simply decline further participation in the case.

Consequence of Providing an Expert Opinion

The authors of the article suggest several considerations that should guide a physician’s ethical judgment about acting as an expert witness. The first requires the physician to consider the consequences to the parties. Testifying that the victim suffered from a mild traumatic brain injury, when the expert doubts that the facts establish such an injury, would undermine the victim’s case, might prolong the litigation, and could cause the victim to suffer further stress as she pins her hopes on unachievable goals.

The expert could also experience professional consequences from giving less than honest testimony, including sanctions imposed by a state licensing board. She might also be sued by the trucking company if she provides false testimony that causes a judgment to be entered against it.

Of course, all of those concerns could be alleviated if the expert testifies truthfully. It seems self-evident that the expert should share her concerns with the attorney who hired her. If the attorney still wants her to testify, she should make clear that she does not know whether the victim did or did not lose consciousness or whether she appeared to be disoriented. She was not present at the accident scene and only the eyewitnesses who were present would have that knowledge.

It is up to the jury, not the expert, to decide the facts of the case. The expert is free to give conditional testimony if she chooses. In other words, the expert can make clear that her opinion is conditioned on certain facts being true, and that she cannot be certain whether the evidence will prove those facts.

Daubert Analysis

The authors suggest that the expert’s opinion would not satisfy the Daubert standard for the admissibility of expert witness testimony. They suggest that:

  • The testimony is not based on sufficient facts.
  • The testimony would not be based on reliable principles and methods.
  • The expert cannot reliably apply scientific principles to the facts of the case.

Whether the authors’ Daubert analysis is correct depends upon the testimony that the expert would give. Whether expert testimony is admissible under Daubert is for the court to decide, not the expert. Whether the attorney will want the expert to testify, after being advised about the expert’s honest opinion, is a question for the attorney to answer, not the expert.

Experts in most states are entitled to answer hypothetical questions. The expert might be asked a question along these lines: “Assuming the victim lost consciousness and experienced disorientation after the accident, do you have an opinion whether the victim’s current headaches and cognitive dysfunction were caused by the accident?” It would then be the attorney’s responsibility to introduce evidence to support those assumptions, which might come from the victim herself.

It is not unethical to give an honest answer to a hypothetical question. An expert neurologist is not a detective. Police reports are not always accurate and conflicting recollections are not uncommon. The expert should disclose her reservations to the attorney who hires her, and if the attorney points to facts suggesting that the victim suffered disorientation and a loss of consciousness shortly after the accident, the expert should feel free to render an opinion based on those facts, while acknowledging in her testimony that whether those facts are true is for the jury to decide.

Professional Guidance

The best advice in the journal article comes from the American Medical Association:

The AMA Code of Medical Ethics Opinion 9.07 expressly states that physicians who serve as expert witnesses must deliver honest testimony grounded in “recent and substantive experience or knowledge in the area in which they testify, and be committed to evaluating cases objectively and to providing an independent opinion.” … The opinion also states that physicians cannot let financial concerns drive the nature of testimony, and it calls on medical professional societies and state licensing board to sanction those who give false or misleading testimony.

In other words, an expert should be competent to render an opinion and should do so honestly. As long as an expert witness follows those simple rules, the expert should have no difficulty meeting ethical standards.

Forensic Lab Tech

Investigation Highlights the Need for Independent Forensic Experts

Most state and local crime lab employees are honest and hard-working, but as federal appellate Judge Alex Kozinski recently noted, some see their job as helping prosecutors obtain convictions, not as finding the truth based on an objective analysis of evidence. Whether from laziness, poor training, misguided loyalty, or pressure applied by law enforcement agencies, government crime lab employees too often produce inaccurate results, and sometimes falsify evidence.

A new investigation suggests that prosecutors have been slow to correct those problems. Until crime labs are able to assure that forensic test results used as criminal evidence are accurate, it will continue to be vital for criminal defense attorneys to retain their own forensic experts to review crime lab results.

Problematic Crime Lab Results

Last year, the Washington Post reported that “nearly every examiner in an elite FBI forensic unit gave flawed testimony in almost all trials in which they offered evidence against criminal defendants over more than a two-decade period before 2000.” The examiners overstated forensic matches of hair comparisons “in ways that favored prosecutors.”

Perhaps the FBI lab employees relied on flawed science, although they should have known that they were basing their conclusions on “incomplete or misleading statistics.” According to the Post, the experts testified as they did because they were trained to give testimony that favored prosecutors.

An article in The Atlantic (“CSI Is a Lie”) reports that many state and local crime lab employees have testified about incorrect or unreliable lab results, usually because of poor training or sloppy work. Cited examples include:

  • In St. Paul, “faulty techniques and ignorance of basic scientific procedures” contributed to “major errors.”
  • In Colorado, inadequate training contributed to errors in the measurement of alcohol in blood samples.
  • An audit in Detroit “uncovered serious errors in numerous cases” due to “sloppy work” that “probably resulted in wrongful convictions.” The police crime lab was shut down as a result of the audit.
  • Three trace-evidence technicians in Philadelphia, charged with examining evidence for traces of blood and semen, flunked their accreditation exams after working for a year, casting doubt on the accuracy of their test results.

Last year, crime lab technicians were found to be tampering with evidence in Oregon and Delaware. A complete list of reported crime lab scandals establishes that the problem has a nationwide scope.

Deliberately False Crime Lab Results

Even more serious are the cases in which crime lab analysts were pressured to lie or to withhold test results that did not support the prosecution’s theory of guilt. The Houston Crime Lab stands as the most notorious example of crime lab analysts who deliberately slanted or fabricated testimony to favor the prosecution. That scandal spurred reform, although the reform efforts did not prevent a toxicologist who testifies for the prosecution in Houston DWI trials from giving false testimony about her credentials.

A more recent example comes from North Carolina, where an independent investigation determined that North Carolina’s State Bureau of Investigation “withheld exculpatory evidence or distorted evidence in more than 230 cases over a 16-year period.”

Three of those cases resulted in executions. There was widespread lying , corruption, and pressure from prosecutors and other law enforcement officials on crime lab analysts to produce results that would help secure convictions. And the pressure worked.

The state’s training manual made clear that the job of North Carolina’s forensic experts was to help secure convictions, not to present objective evidence so that a jury could find the truth.

Prosecutors Resist Remedies

Perhaps the most shocking example of dishonesty occurred in Massachusetts, where drug lab analyst Annie Dookhan made it her mission to get drug users “off the streets.” The easiest way to accomplish that mission was to falsify “tens of thousands of reports, often marking results as ‘positive’ without testing a substance.” Dookhan served a short prison sentence for committing perjury, but tens of thousands of defendants who were convicted and sentenced on the basis of falsified lab test results have never received a remedy.

The ACLU and other organizations have asked the court system to vacate 24,000 Massachusetts convictions that were tainted by Dookhan’s fraudulent reports. Prosecutors, however, have resisted that request, arguing that each defendant should file his or her own motion to challenge the conviction, a process that would take years while overwhelming the state’s public defender system.

An investigation by ProPublico found that prosecutors initially denied that they had any obligation to inform potentially innocent defendants that fraudulent evidence may have contributed to their convictions. After resisting that obligation for four years, prosecutors finally mailed a notice that failed to identify the sender and lacked essential information. Thousands of those notices were returned as undeliverable.

ProPublica notes that the reluctance of prosecutors to disturb convictions based on tainted evidence is not limited to Massachusetts. For example, many convictions have been based on unreliable field tests for drugs that are never confirmed by crime lab testing, but prosecutors in Las Vegas and Houston have been slow to track down individuals who were wrongly convicted.

It is understandable that prosecutors want convictions of guilty defendants to stand, but those convictions should not be based on unreliable or fraudulent forensic evidence. As Matthew Segal, the legal director of the ACLU of Massachusetts, said: “If you think that the person is guilty, then your obligation is to go out and get a clean conviction, not to protect the dirty conviction, the tainted conviction.”

Solving the Problem

When crime labs are dedicated to serving the police, and particularly when they are part of a police agency, experts are more likely to see themselves as advocates for the police rather than advocates for the truth. That problem prompted the National Academy of Sciences to recommend making the government’s forensic experts administratively or financially independent of law enforcement agencies.

Until that happens, the important role played by private forensic experts in a criminal case cannot be overstated. Defense attorneys can no longer assume that a report prepared by a crime lab analyst is accurate or unassailable. Retaining a private expert to conduct an independent analysis of forensic evidence is often a critical means of fulfilling a defense attorney’s duty to provide effective representation to the accused.

Policeman standing with crossed arms

Scholar Examines Whether Police Officers Are Helpful to Juries As Expert Witnesses

Anna Lvovsky examines  the origins and scope of the judicial presumption of police expertise for the Harvard Law Review.

History of Police Expertise in Courts

Lvovsky asserts that the idea of a police officer as an expert developed out of the police professionalization movement, which gained prominence in the 1950s. Trial court judges began to welcome police officers as expert witnesses on crime. Subsequently, courts began to use police officers as expert witnesses to analyze probable cause and authorize investigatory stops. Finally, police expertise was relied upon to act as a check against the risk of arbitrary enforcement and to “salvage” controversial statutes from vagueness.

Lvovsky argues that the professionalism movement was centered upon the expertise of the members of the occupation, a commitment to higher values, and bureaucratic organization and freedom from external influence. She asserts that the professionalism movement’s most successful efforts were the internal restructuring of police departments, including centralizing authority with police chiefs, limiting police tasks to crime prevention, and dividing work into different specialized departments.

Lvovsky asserts that police expertise comes from basic experience and education, both in conjunction with universities and in independent police academies.

Police, Public Relations, and the Courts

According to Lvovsky, once the caliber of the police form was improved, reformers wanted credit for it. In the 1930s, the International Association of Police Chiefs (IACP), the most prominent national organization in the police reform movement, organized a public relations committee and began to reach of to the media to pitch flattering articles about police departments while downplaying reports of misconduct. Locally, representatives of local police departments began similar public relations campaigns.

In the 1950s, the professionalism movement began to advocate to the courts. Beginning in the mid-1950s, a series of constitutional decisions that limited police investigative powers created an “uproar” among the police communities. Mallory v. United States restricted the right of officers to interrogate suspects prior to arraignment and Mapp v. Ohio required the exclusion of evidence when officers violated the Fourth Amendment.

In response to Mapp, police advocacy groups warned that such cases undervalued police authority and rendered “good police work meaningless and police experience as worthless.” Professionalism advocated began to advocate directly to the judiciary, inviting them to speak at police conferences and participate in round-table discussions “to encourage a two-way flow of information” as an ‘effective device’ for addressing unfavorable judicial rulings.”

Lvovsky opines that the police reform and professionalism efforts had some success. As a general rule, police began to keep better records, conducted more systemic investigations and were free from excessive political meddling. Police officers were generally seen as more competent and harder workers. In 1947, a survey of occupational prestige ranked police 55 out of 90. In 1963, police ranked 47 out of 90.

Police as Experts

Lvovsky questions whether the modern trend of asking police to testify as experts on complex issues ranging from gambling to prostitution to narcotics is helpful to courts and asserts that the reliance upon police expertise in these diverse areas may not have a sound basis.

Anna Lvovsky is an Academic Fellow at Columbia Law School. She focuses on criminal law and procedure, constitutional law and evidence, especially the legal and cultural dimensions of policing, judicial uses of professional knowledge, and the resolution of gender, sexuality, and morality. Her article is forthcoming in a 2017 Harvard Law Review Journal.

Gavel and Stethoscope on Reflective Table

Appellate Court Allows Medical Expert to Testify in Indiana Malpractice Case

Several states have adopted laws that require medical malpractice allegations to be reviewed by a panel of healthcare providers before a malpractice lawsuit can be filed. Construing Indiana’s version of that law, the Indiana Court of Appeals recently decided that an expert witness would be allowed to testify at trial about a theory of medical malpractice that was not expressly presented to the review panel.

Allegations of Malpractice

Rowena Turner was diagnosed with a form of bone marrow cancer that increased her risk of developing blood clots. She was prescribed anticoagulant (blood thinner) medication to reduce that risk.

Ten years later, Dr. Charles McKeen performed surgery to remove a part of Turner’s colon. When she was discharged, Dr. McKeen told her not to restart her anticoagulant medication.

Two days after her discharge, Turner was readmitted to the hospital with complaints of vomiting. Based on her distended abdomen, Dr. McKeen concluded that she suffered from a small bowel obstruction. Later that day, Turner was transferred to a critical care unit after her blood pressure dropped. She was diagnosed with deep vein thrombosis, a condition that occurs when a blood clot forms in a deep vein, and with acute kidney failure. Turner died about a week later.

Following Indiana’s procedure for bringing a medical malpractice claim, Turner’s husband filed a proposed complaint with the Indiana Department of Insurance. The complaint alleged that Dr. McKeen was negligent and that his negligence caused Turner’s death. Turner’s husband later filed a submission with the Medical Review Panel (MRP), supported by medical records, that explained his theory of Dr. McKeen’s negligence.

The submission to the MRP focused on Dr. McKeen’s failure to perform exploratory surgery promptly after Turner’s readmission to the hospital. The submission did not allege that Dr. McKeen was negligent in the dosage of anticoagulant medication he prescribed during the first hospitalization or in his instruction to forego blood thinners after Turner’s discharge.

The MRP concluded that Dr. McKeen was not negligent. Having jumped through the procedural hoops that Indiana requires before medical malpractice litigation can be commenced, Turner’s husband filed his lawsuit.

Expert Opinion

During discovery, Turner’s husband obtained and furnished the report of an expert hematologist, Dr. Robert Manges. Dr. Manges expressed the opinion that Dr. McKeen negligently failed to provide a proper dosage of anticoagulant medication during Turner’s first hospital stay, given her elevated risk of forming blood clots. Dr. Manges also opined that Turner would not have developed deep vein thrombosis if she had been prescribed an appropriate dosage of anticoagulants after her hospital discharge.

Dr. McKeen’s attorney filed a motion to strike Dr. Manges’ opinions because his theory of malpractice had not been presented to the MRP. The trial court granted that motion but later reconsidered its decision. When it ordered that Dr. Manges would be permitted to testify, Dr. McKeen asked the Indiana Court of Appeals to review that order prior to trial. The Court of Appeals agreed to do so.

Court’s Ruling

After filing a proposed complaint, Indiana law requires a plaintiff to submit evidence in support of the complaint to an MRP. The evidence must pertain to the theory of negligence that will be raised at trial.

The MRP, which consists of three physicians, then renders an expert advisory opinion about the complaint’s merit. The MRP essentially gives a thumbs up or a thumbs down to the complaint but it does not explain its reason for doing so. The opinion has no impact on the plaintiff’s right to file a lawsuit, but it must be obtained as a condition of filing suit.

Attorneys often accompany the evidence with a statement that explains why, in their opinion, the case has merit, but the law does not require them to do so. The Court of Appeals concluded that such statements are not “evidence” and that the failure to explain all the ways (or any way) in which a doctor was negligent has no bearing on the ability to raise those theories of negligence at trial. Turner’s husband was therefore not precluded from contending that malpractice occurred for reasons that were not addressed in the statement submitted to the MRP.

The court also concluded that the proposed complaint filed with the MRP does not need to articulate specific theories of negligence. In Indiana, a complaint merely serves to give notice to the party being sued of the general claim (in this case, malpractice) that is being made. Complaints need not recite evidence in support of the claim.

The complaint filed by Turner’s husband met the notice standard. It alleged that Dr. McKeen was negligent by failing to provide the appropriate standard of care to Turner during a time span that covered both hospitalizations.

The decisive question was whether evidence of the theory of negligence that would be raised at trial was presented to the MRP. There was no question that Dr. Manges’ expert opinion was not included in the evidence submitted to the MRP.

The court held that medical malpractice plaintiffs are not required to provide all of their evidence, including expert opinions, to the MRP. The panelists, after all, are themselves experts. Plaintiffs need only present some evidence that supports the theory of malpractice that will be raised at trial.

Turner’s husband did that by submitting Turner’s complete medical records, which included the anticoagulant dosage that Dr. McKeen ordered during her first hospitalization, as well as his instruction to discontinue the medication after her discharge. Since those are the facts upon which Dr. Manges based his expert opinion, the Court of Appeals agreed that the expert could not be precluded from rendering that opinion at trial.

Criminal Forensics, word cloud concept 11

Expert Scientific Report Issues Scathing Review of Common Forensic Techniques

Recently, the President’s Council of Advisors on Science and Technology (PCAST) released an expert witness report  which sharply criticized a number of widely accepted forensic methods used in criminal trials. As expert witnesses become ubiquitously integrated into the American criminal justice culture, many forensic science techniques have become commonplace in trials, and the PCAST report represents an effort to trim so-called junk science from the courtroom.

Increased Scrutiny Raises Questions about Forensic Science Techniques

After experiencing a heyday of expansion in the 1990s, expert forensic science testimony used during criminal trials has seen a rise in scrutiny from the scientific community from the early-2000s through the present. Commonly used forensic analysis procedures such as bite-mark analysis, footwear examination, and microscopic hair comparisons have been widely criticized by scientific experts, and even widely accepted techniques such as DNA analysis and latent fingerprint identification have undergone rigorous scientific study in order to determine when and how such procedures are effective and valid. Among the number of studies conducted which analyze the validity of forensic evidence, a handful stand out:

  • In 2002, the FBI found that 11% of its microscopic hair comparisons incorrectly matched hair samples, and in 2015 a report by the FBI and the Innocence Project found that hair matching analysis was incorrect a staggering 90% of the time;
  • In 2004, a report commissioned by the FBI found that there was insufficient research and data to match bullets based on lead composition;
  • In 2005, a review of latent fingerprint testing used in the investigation of an alleged terrorist in Spain found that police bias allowed for the fingerprint evidence to be misinterpreted, and several studies throughout the mid to late 2000s have identified causes of error in fingerprinting which have refined the process;
  • Several studies since 2009 have found bite mark evidence to be unreliable in identifying defendants; and
  • Multiple studies and reports by the FBI and the National Institute of Justice have found that DNA testing has invalidated jail sentences for several defendants who were convicted on the strength of faulty bite mark, hair comparison, shoe tread comparison, and other common forensic methods.

Since the turn of the century, a cottage industry has arisen for scientists and legal organizations dedicated to re-evaluating convictions based on shaky forensic expert witness testimony, leading to several hundred exonerations across the United States. With widely accepted forensic methods facing questions from the scientific community, President Obama commissioned PCAST in 2015 to write a report which critically examined the state of forensic methods used in criminal trials.

PCAST Report Sharply Criticizes Common Forensic Methods

Last week’s PCAST report , which was written by high profile scientists who conducted thorough reviews of forensic techniques and methodology, issued a critical review of several types of evidence which have become common in criminal trials. Building on prior work and conducting further empirical research, the PCAST report critically examined 7 forensic methods: single source DNA testing, complex multi-source DNA testing, latent fingerprinting, bite mark, firearm analysis (which connects a bullet to a gun based on unique features of the weapon), footwear analysis, and hair matching analysis.

The report found that single source DNA testing is a highly valid forensic method and both multi-source DNA and latent fingerprint analysis have made strides in refining the process and there are reliable experts available to testify to each method in criminal trials. The scientific experts who generated the PCAST report concluded that bite mark identification, firearm analysis, footwear tread identification, and hair matching analysis are currently unreliable given the lack of empirical research supporting each field. The PCAST suggested opportunities for improvement, particularly in firearm analysis, but suggested that each of these forensic techniques must undergo more rigorous testing before being universally relied on in criminal trials.

Implications of the PCAST Forensic Expert Report

Since 1993’s Daubert v Merrell Dow decision, judges throughout the American legal system have been tasked with rigorous evaluation of expert witness testimony and are only allowed to admit experts who provide reliable testimony that is the product of sound theory and scientific methodology. Judges can consider many factors, but in reality asking the judiciary to critically evaluate scientific work imposes a duty beyond a judge’s qualifications. As a result, forensic methods based on junk science can gain widespread popularity if a collection of scientists convince a judge that the theory and methodology are sound enough to pass legal muster.

The PCAST report, which is written with an eye towards the legal standard for admitting forensic expert witness evidence, provides judges with the tools necessary to more closely evaluate many widely used forensic techniques. While the future use of these common forensic techniques in courtrooms is unlikely to change overnight, the long term effect of the PCAST work will likely see a decrease in reliance on unreliable forensic expert testimony. Regardless of its immediate effect, the PCAST report represents a change in how the scientific and legal community will interact in criminal investigation and prosecution as more rigorous scientific analysis influences when and how expert witnesses can testify.

eye looking through peephole

Eyewitness Identification Experts Are Making a Difference in Illinois

American courts have been slow to recognize the importance of expert opinions when a criminal charge hinges on eyewitness testimony. Until recently, judges tended to rule that juries understand the possibility of mistaken eyewitness identifications and that experts had nothing meaningful to add to jurors’ knowledge.

Mistaken eyewitness identifications are the leading cause of wrongful convictions of innocent defendants. As DNA testing continues to expose wrongful convictions, courts are increasingly acknowledging the reality that jurors really don’t understand how easily an eyewitness can make a mistaken identification. Exonerations, coupled with published studies that explain why eyewitnesses so often get it wrong, have compelled courts to recognize that a defendant who wants to call an eyewitness identification expert probably won’t receive a fair trial unless the expert is permitted to testify.

Illinois Opens the Door

The Illinois Supreme Court opened the door to testimony by eyewitness identification experts in a ruling earlier this year. In an appeal from a murder conviction, the court agreed that the defendant, Eduardo Lerma, was denied a fair trial when the trial judge refused to allow his expert witness to testify.

The only evidence against Lerma consisted of eyewitness identification testimony. The key witness testified that she was standing on the unlit steps of a home near midnight when she saw a man dressed in a black hooded sweatshirt draw a gun and shoot the victim. The victim then fell on top of the witness, who heard the victim say “Lucky shot me.” The defendant was known in the neighborhood as “Lucky.”

The eyewitness had never met the defendant but had occasionally seen him on his porch across the street. Depending on whether her trial testimony or her prior grand jury testimony is to be believed, she only saw the defendant on his porch once or twice, or as many as ten times. She had never spoken to him and had not seen him in six months to a year prior to the shooting.

The Proposed Expert Testimony

The defendant wanted to call a psychologist as an expert witness to testify about several facts that typical jurors do not understand. Those facts included: an eyewitness’ confidence in her identification does not correlate with the accuracy of the identification; the stress of witnessing a violent crime, the presence of a gun, nighttime viewing, and the passage of time all affect an eyewitness’ ability to make an accurate identification; cross-racial identifications are less reliable than same-race identifications; and eyewitness identifications are influenced by suggestion (such as “Lucky shot me”).

The expert acknowledged that identifications are more reliable when the eyewitness knows the person she is identifying. For that reason, the trial judge excluded the expert’s testimony on the ground that it wasn’t helpful to the jury. The judge also remarked that identification experts were simply “the latest trend.” The defense asked the judge to reconsider, offering the opinion of another psychologist that acquaintance with the person being identified does not necessarily increase the reliability of the identification. The trial judge refused to permit any expert testimony.

The Supreme Court’s Ruling

The Illinois Supreme Court decided that the expert’s testimony should have been admitted. The court recognized that in the 25 years that had passed since it last ruled on the admissibility of expert testimony concerning eyewitness identification, a growing body of relevant research had produced “a dramatic shift in the legal landscape,” as courts across the country have come to regard expert testimony as both reliable and necessary to a fair trial when the defendant’s identification is in doubt.

The court noted that most of the factors that render an identification questionable were present in Lerma’s case. The court also concluded that whether or not eyewitness identification is more reliable when the witness knows the person she identifies, it was not fair to say that the eyewitness who identified Lerma actually knew him. Seeing a person from a distance a few times is not the same as knowing a person, and the witness expressly testified that she did not know Lerma. Expert testimony was therefore an essential means of explaining to the jury why the eyewitness identification might have been mistaken.

The Impact of the Lerma Decision

The Chicago Tribune points out that eyewitness identification experts have made a difference in Illinois trials. Marco Lopez was recently acquitted of murdering a father and son after an expert witness explained why an eyewitness identification could not be trusted.

The case against Lopez rested on eyewitness testimony. The murder weapon was never found and Lopez’ DNA was not present at the crime scene. The police questioned and released a different suspect who may have committed the crime. Two people who told the police that they saw Marco with a gun on the night of the murder changed their stories when they testified under oath.

The eyewitness testified that he saw Lopez walking away from the crime scene “from about 10 feet away through a glass door shortly after midnight.” The expert explained how poor lighting, the brief observation, and other factors cast doubt on an identification made under those conditions.

The Tribune article cites a number of wrongful convictions in Illinois that were based on mistaken identifications before the Lerma case opened the door to expert testimony. Now that jurors are being made aware of factors that make identifications doubtful, expert witnesses are helping to assure that fewer innocent defendants are convicted in Illinois courts.