Tuala Auimatagi is accused of committing two murders in August 2019. The first charge involves a drive-by shooting in West Sacramento. The second shooting took place a week later in Richmond, California. Both victims were shot with a rifle.

No eyewitness identified Auimatagi as the shooter in West Sacramento. The only eyewitness to the Richmond shooting was the victim’s girlfriend. She told a police detective that Auimatagi broke into her home to retrieve a handgun that she had given to the victim. The victim’s girlfriend claimed she saw Auimatagi shoot the victim. However, the girlfriend died before the case went to court, leaving the prosecution with no eyewitness.

The prosecution was able to use the girlfriend’s hearsay statement at a preliminary hearing. Based on that statement, the court found that there was probable cause to charge Auimatagi with the Richmond homicide.

Forensic Expert’s Opinion

Images from street cameras established that Auimatagi was in a black BMW on nearby roads in West Sacramento on the day of the first shooting. The prosecution relied on the expert testimony of Alex Taflya to link Auimatagi to that shooting.

Taflya is a forensic expert employed by the Yolo County Sheriff’s Office. He compared the bullets that killed both victims. Tayfla testified that the two bullets shared markings that suggested they were fired from the same firearm. However, Tayfla could not evaluate the firearm and therefore could not be certain that the bullets were fired from the same gun.

Tayfla testified that, assuming the similar markings were not made by characteristics that are common to the same make and model of firearm, they were fired by the same gun. In the court’s view, Taflya’s testimony was sufficient to establish probable cause to support the prosecution’s charging decision. Whether that testimony would be admissible at trial was a separate question.

Subclass Markings

Fans of the CSI series might believe that ballistics is a rigorous science. A critique of firearms identification prepared by a committee of the National Research Council (NRC) in fact been described ballistics as “part science and part art form.”

Markings are made on bullets as they travel through the barrel of a gun. Some of those markings (known as class characteristics) might be made by thousands of firearms of a particular model and manufacturer. Other markings (known as individual characteristics) are made by particular guns and may be unique to an individual gun.

In a middle range between class characteristics and individual characteristics are subclass characteristics. The NRC notes that subclass characteristics are caused by the gun’s manufacturing process. They may be present in only a small subset of guns that were manufactured in the same place and at the same time, but they are not uniquely caused by a particular gun. Two different guns can produce identical subclass characteristics.

The Limits of Firearms Identification Evidence

The NRC review makes clear that it is impossible to be certain that two bullets were fired from the same gun without examining every gun that could have fired the bullets. The fact that two bullets share similar markings does not rule out the possibility that they were fired from two guns that happen to cause similar markings. The President’s Council of Advisors on Science and Technology (PCAST) agreed that ballistics evidence, like much other evidence involving forensic standards, is too subjective to produce consistently reliable results.

In addition, to know whether markings are individual characteristics or subclass characteristics, it is necessary to know the manufacturer and model of the gun from which the bullet was fired. Firearms examiners can generally rule out the possibility that two bullets were fired from the same gun when their markings are different. Concluding that two bullets were fired from the same gun is much more difficult. It is usually impossible to draw that conclusion with any certainty if the examiner does not have the gun from which the bullets were fired.

Expert Opinion Limited

As Auimatagi’s case approached trial, his lawyers filed a motion to exclude Talfya’s opinions on the ground that they were not reliable. The trial judge decided that Talfya would be allowed to testify, but that his testimony will be limited.

The judge decided that Talfya can testify that he saw similar markings on the bullets recovered in the two shooting. The judge allowed Talfya to describe how guns leave markings on bullets. Talfya will also be allowed to testify about the characteristics of the markings he saw on each bullet.

Talfya will not be allowed to testify, as he did in the preliminary hearing, that the bullets came from the same gun “assuming” that the similarities were not characteristics produced by all guns within the same subclass. The judge recognized that Talfya’s assumption was “not supported by the facts or the science and misstates the level of scientific certainty of his findings and is therefore misleading.”

If he is asked on direct or cross-examination, Talfya will also be allowed “to testify that he cannot exclude or eliminate the bullets as coming from different guns.” He “will not be permitted to describe any greater level of scientific certainty than the bullets may or may not have come from the same gun.” Since Talfya doesn’t know whether the bullets came from the same gun, he shouldn’t be permitted to hint that they probably did.

Lessons Learned

The defense relied on two expert witnesses, Dean David Faigman and Nicholas Scurich. Faigman was a Senior Advisor to the PCAST Report, “Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature-Comparison Methods.”

The Auimatagi prosecution underscores the importance of consulting with a defense expert whenever the prosecution relies on a forensic expert. Expert witnesses can provide vital testimony at trial to counter the prosecution expert’s opinions.

As importantly, defense experts can support a challenge to the admissibility of a prosecution expert’s testimony. Given the tendency of prosecution experts to overreach, employing a defense expert early in the case can assure that juries never hear harmful opinions that amount to improper speculation.

Beverly Bowers sued Andrew Tillman for negligence. Tillman was driving a truck in Florida that collided with Bowers’ vehicle. Bowers contended that Tillman’s negligence caused painful injuries to her neck and back, including migraine headaches. The defense argued that those symptoms were caused by a preexisting condition.

At her initial trial, the lawyers for both sides engaged in gladiatorial behavior. They were rude to each other, sometimes in the presence of the jury. After five days of trial, the trial judge had enough and granted a mistrial.

The unprofessional conduct continued in the second trial. At the end of the trial, the jury awarded Bowers $58,248 for her past medical expenses and $27,300 in lost wages. The jury determined that her injuries were not permanent and awarded her nothing for future medical care or loss of earning capacity. Remarkably, the jury made no award for pain and suffering.

Bowers moved the trial court for a new trial. She based her motion in part on improper comments made by an expert witness for the defense. The judge denied the motion and Bowers appealed.

Defense Expert’s Comments

Dr. Robert Kowalski testified as an expert for the defense. Prior to trial, Bowers asked the court to exclude any testimony referring to matters outside the record. The court granted that motion. In particular, the court precluded any reference to the content of medical records that Dr. Kowalski had not seen.

The defense had complained that Bowers did not produce her chiropractic records. The court ruled that the defense could not speculate that the records would “show x, y, or z about the Plaintiff” or to argue “we just don’t know because the Plaintiff did not give them to us.”

Notwithstanding that order, Dr. Kowalski testified on direct examination that he believed certain records of Bowers’ chiropractic treatment would support his opinion that her injuries were caused by a preexisting condition. The records were not in evidence and Dr. Kowalski’s suspicions about their content were therefore unsupported.

Dr. Kowalski’s testimony was a blatant violation of the order limiting his testimony. Whether Dr. Kowalski was aware of that order was unclear to the appellate court, but ignorance is no defense. The insurance defense lawyer had a duty to instruct Dr. Kowalski to follow the court’s order. Whether the fault lay with the lawyer or the expert witness has no bearing on whether the improper testimony deprived Bowers of a fair trial.

Bowers objected to the testimony. The court sustained the objection and instructed the jury to disregard the comments. The court denied a motion for a mistrial.

Hidden Medical Record

Bowers originally claimed that certain abdominal symptoms were caused by the accident. She withdrew that claim well before trial. The court entered an order prohibiting reference to her abdominal issues.

Tillman’s attorney assembled a 140-page exhibit that purported to include medical and billing records related to Bower’s injury claims. In the middle of that exhibit, the attorney buried a single page from a urology record that related to the abdominal treatment. Bowers’ attorney did not notice that the page was included in the lengthy exhibit.

During his closing argument, the defense attorney placed the urology record on a screen for the jury to view. The attorney directed the jury’s attention to a urologist’s comment that Bowers’ attorney had referred Bowers to a chiropractor. After Bowers objected, the defense lawyer continued to display the exhibit to the jury until the court ordered him to shut off the display.

No other evidence at trial suggested that Bowers saw a chiropractor at the suggestion of her attorney. The court determined that defense counsel deliberately smuggled an improper exhibit into the compilation of medical records so that he could present otherwise inadmissible evidence to the jury during his closing argument. The court ordered the urology record to be removed from the exhibit, ordered defense counsel not to comment upon it further, and instructed the jury to disregard it.

Appellate Decision

As the appellate court recognized, Dr. Kowalski’s testimony about the presumed content of the chiropractic records bolstered his opinion about a preexisting condition. It was clearly improper to violate an order that was entered to protect Bowers from improper speculation about the content of records that Dr. Kowalski had never seen.

The improper testimony was compounded by defense counsel’s reference to a urology record that he buried in the middle of a compilation of medical records. The appellate court condemned counsel’s “gotcha” tactic and observed that lawyers, as officers of the court, have a special duty “to avoid conduct that undermines the integrity of the adjudicative process.” Defense counsel fell well short of fulfilling that duty.

In her motion for a new trial, Bowers argued that the trial court should take notice of other cases in which defense counsel had engaged in improper trial tactics that prompted a new trial. The trial judge decided that the bar association, rather than the court, should determine whether counsel had engaged in a pattern of misconduct. The appellate court held that the trial court did not err by basing its decision on the case before it rather than other cases in which defense counsel participated.

The ultimate question before the appellate court was whether the expert’s improper testimony, combined with the improper closing argument, deprived Bowers of a fair trial. The jury’s failure to award her any compensation for pain and suffering is strong evidence that the jury believed Bowers was unworthy of compensation. The improper expert testimony and closing argument would be a reasonable explanation of the jury’s conclusion.

The appellate court, however, decided that the trial judge was in the best position to decide whether the improper conduct probably had an impact on the jury. That’s true, but it is likely true that the trial judge didn’t want to preside over another contentious trial involving the same lawyers. The appellate court did not evaluate the trial court’s reasoning. It also failed to offer any alternative explanation for the jury’s failure to award damages for pain and suffering after awarding substantial compensation for medical expenses and lost wages. Whether the appellate court reached the correct result is difficult to determine when the appellate court defers to a decision that it fails to analyze.

Lessons Learned

A lawyer might be tempted to learn from the Bowers decision that introducing inadmissible testimony through an expert witness is the path to victory. A better lesson to learn is that lawyers jeopardize their reputations by engaging in sharp practices.

It isn’t clear whether the expert knew about the order limiting his testimony. It therefore isn’t clear whether the expert knowingly did anything wrong. It is nevertheless a lawyer’s duty to acquaint a testifying expert with limitations that a court has imposed on the expert’s testimony. A lawyer’s failure to do so places a favorable verdict at risk. While the improper expert testimony did not lead to a new trial in Bowers’ case, lawyers should never assume that eliciting improper testimony from an expert witness will have no consequences.

Medical examiners are employed by state and local governments to determine a cause of death. Television shows tend to portray medical examiners as forensic detectives. While medical examiners often find information that helps investigators solve crimes, their mission is simply to determine why someone died.

In routine cases, the cause of death is not a mystery. Most states require an autopsy to be performed when the cause of death is suspicious or unknown. Medical examiners often perform autopsies when a death probably resulted from homicide, suicide, an accident, or an occupational hazard. In those cases, a medical examiner typically dissects and examines the body and reviews results of lab tests to determine why a person died. Sometimes the medical examiner will need to sort through multiple causes to determine whether any of them would have been sufficient to cause death in the absence of the others.

In some cases, the cause of death is disputed. Those disputes may arise in criminal cases or in wrongful death lawsuits. When a medical examiner draws conclusions from medical evidence that is open to interpretation, a party may retain a pathologist as an expert witness to offer alternative explanations for a death. It is then up to a jury to decide whether to accept the medical examiner’s opinion.

The Importance of a Second Opinion

While medical examiners are usually reliable witnesses, no witness is infallible. In homicide prosecutions, defense attorneys often submit autopsy reports to independent pathologists to determine whether the medical examiner’s opinion is open to doubt.

Writing for MedPage Today, Dr. Judy Melinek relates the story of a forensic pathologist who was asked by the family of a man who died in police custody to perform a second autopsy. The pathologist noted that the man’s neck had not been fully dissected. When she opened the neck, she found a bag of drugs that was blocking the back of the man’s throat. The pathologist who performed the first autopsy missed a likely cause of death.

The privately retained pathologist told Dr. Melinek that she was accused of planting the drugs. Since autopsies are usually performed in the presence of photographers and lab assistants, planting evidence would typically be a difficult task. Nor was there any reason to believe that the private pathologist had any incentive to do so.

According to Dr. Melinek, however, attacks upon the integrity of privately retained experts are common. One pathologist, for example, discovered a broken hyoid bone that the first autopsy missed. A fractured hyoid bone is rare and is typically caused by strangulation. The pathologist who found the fracture was accused of breaking the bone himself. He was eventually exonerated, but only after years of fighting the false accusation. The accusation has followed the pathologist, making lawyers reluctant to hire him as an expert witness.

The Ethics of Testifying

Medical examiners work for the government. They don’t work for prosecutors. Their job is to advance the truth, not to advance a prosecution. Unfortunately, as Dr. Melnick points out, “there is a subset of prosecutors who believe, and will not be dissuaded, that the investigative work done by a medical examiner always ought to align with the goals of law enforcement. Some forensic pathologists feel the same way.” Those pathologists serve a law enforcement agenda when discovering the truth should be their only agenda.

Dr. Melnick reports that some medical examiners refuse to speak to defense attorneys. A medical examiner should have nothing to hide. Refusing to discuss findings with a defense attorney sends the message that the medical examiner is an advocate for the prosecution rather than an advocate for the truth.

Doctors who are employed by the government sometimes disparage forensic pathologists who are hired by defense attorneys. In fact, an expert who is called to testify by a defense lawyer is bound by the same ethical obligations that should govern the testimony of a medical examiner. The primary obligation is honesty. When a cause of death is a matter of probability and other causes remain possibilities, an honest witness should readily admit that fact.

When Dr. Melnick worked as a pathologist for a medical examiner’s office, she did some consulting work in civil and criminal cases, including work for prosecutors in other counties. Her employer told her that her testimony created a conflict of interest. In fact, there is no conflict in testifying for “the other side” because the truth does not take sides. As Dr. Melnick puts it, “We are neither defense witnesses nor prosecution experts. We are witnesses for the voiceless. We speak for the dead.”

Government employers that restrict the work of pathologists are interfering with a justice system that depends on the honest testimony of expert witnesses. Government employees who launch “whisper campaigns” to destroy the reputations of pathologists who give honest testimony for other parties place their own reputations, and the reputations of honest colleagues, at risk. Nobody trusts an expert who makes groundless attacks upon other experts simply because they follow the evidence to the truth that it reveals.

The Michigan Court of Appeals has thrown out a jury’s guilty verdict and granted a new trial after determining that a doctor’s testimony went beyond the scope of what doctors may testify about in criminal sexual conduct cases.

The Crime

A minor child accused Ryan William Cole, 37, of sexually assaulting her three times in 2014. She claims that she told her mother and other relatives about the first incident, but not the others. Her mother claims that the girl never told her about the abuse and that she had learned about the allegations after a claim was made with Child Protective Services.

The Trial

Prosecutors retained Dr. Lisa Markman to testify as its expert witness. At the time of the trial, Dr. Markman was serving as an assistant professor of pediatrics and the associate medical director of the Child Protection Program at C.S. Mott Children’s Hospital at the University of Michigan in Ann Arbor.

At trial, Dr. Markman testified that she had interviewed and physically examined the girl. Dr. Markman testified that the girl told her that Cole had sexually abused here when she was 5 and 6 years old. She also testified that she did not observe any physical signs of abuse and that she concluded that the girl had been sexually abused solely on the basis of the girl’s account of the alleged incidents.

A Lenawee County Circuit Court jury found Cole guilty of two counts of first-degree criminal sexual conduct involving a person younger than 13. Circuit Judge Margaret M.S. Noe sentenced Cole to 25 to 75 years in prison.

The Court of Appeals

Cole appealed to the Michigan Court of Appeals and it denied his appeal. He appealed to the Michigan Supreme Court, which returned the case to the Court of Appeals to determine whether the prosecution’s expert witness had impermissibly vouched for the credibility of the alleged victim.

Upon review, the Court of Appeals determined that Dr. Markman had impermissibly offered testimony about the credibility of the alleged victim beyond what doctors are allowed to testify about in criminal sexual conduct cases.

Court of Appeals Judges Cynthia Diane Stephens, Deborah A. Servitto, and Anica Letica noted that Michigan Rules of Evidence and two earlier court opinions say that one witness is not permitted to comment on the veracity of another witness’ testimony because credibility matters are to be determined by the jury.

Here, the case “turned on the jury’s assessment of the victim’s credibility because there was no physical evidence, no witnesses to the alleged assaults, no inculpatory statements, and the defendant denied the allegations.” Since Dr. Markman’s opinion was based on the girl’s account of the incidents and her opinion of the girl’s truthfulness, her testimony violated the principle that “an examining physician cannot give an opinion on whether a complainant had been sexually assaulted if the conclusion is nothing more than the doctor’s opinion that the victim had told the truth.”

The Court of Appeals threw out the jury’s guilty verdict and sent the case back to circuit court for a new trial.  Lenawee County was not conducting jury trials during the COVID-19 pandemic; however, its numbers have declined below the threshold for conducting jury trials. Because this case is from 2014, it will be the first trial on the schedule once the county gets the go-ahead from the Michigan State Court Administrative Office.