Author Archives: T.C. Kelly

About T.C. Kelly

Prior to his retirement, T.C. Kelly handled litigation and appeals in state and federal courts across the Midwest. He focused his practice on criminal defense, personal injury, and employment law. He now writes about legal issues for a variety of publications.

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.

DNA

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.

Hypothetical

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.

Meade and Prettyman Courthouse

D.C. Court of Appeals Adopts Daubert

The court that first adopted the Frye standard of expert witness admissibility has formally jettisoned that standard in favor of the Daubert standard. The D.C. Court of Appeals has now joined the federal courts and the majority of states in accepting Daubert as the standard under which the admissibility of expert testimony should be evaluated.

Evidence in the D.C. Court System

The District of Columbia Court of Appeals, like the District itself, is an oddity in American law. The District falls under federal jurisdiction but in most respects it operates as a state. An elected D.C. Council has the power to pass laws, but the laws are subject to the approval of Congress. The District’s trial courts, although operated by the federal government, are separate from the federal courts that decide federal cases. Trial court decisions in the District are appealed to the D.C. Court of Appeals, which describes itself as “the equivalent of a state supreme court.”

The District has not codified its own rules of evidence. Courts in the District are not bound by the Federal Rules of Evidence, although they often turn to the federal rules for guidance. In many instances, the D.C. Court of Appeals has adopted the federal rule, although sometimes in modified form to retain elements of common law rules it has historically followed.

The Competing Standards of Frye and Daubert

The Frye standard for the admission of expert testimony asks whether the expert’s opinion was based on principles that had been generally accepted within the relevant scientific community. The Frye standard was created by the D.C. Court of Appeals in Frye v. United States, a case it decided in 1923. Most states adopted the Frye standard in the years that followed.

State court reliance on the Frye standard changed dramatically after the United State Supreme Court decided Daubert v. Merrell Dow Pharmaceuticals. The Daubert decision interpreted Rule 702 of the Federal Rules of Evidence to require a broader test for expert evidence admissibility than Frye imposed. Under Daubert, judges ask whether the expert’s opinion is based on sufficient facts or data, whether the proposed evidence is based on a reliable methodology, and whether the expert has reliably applied the methodology to the facts.

Unlike the Frye standard, the Daubert standard does not require expert opinions to be based on theories that have gained widespread acceptance, provided that the expert applied a reasonable methodology in a reasonable way to facts that are sufficient to allow the expert to form an opinion. In that sense, Daubert broadened the universe of admissible expert evidence, although many of its proponents praise it for narrowing the range of “junk science” and other unreliable expert evidence that can be admitted in a trial.

Motorola v. Murray

All of the judges on the D.C. Court of Appeals participated in the court’s decision in Motorola v. Murray. The case involved a claim that long-term exposure to cell-phone radiation causes brain tumors. After weeks of pretrial hearings, the trial judge decided that most of the testimony offered by the plaintiffs’ experts would be admissible under the existing Frye standard, but most would be inadmissible under a Daubert standard.

According to the trial judge, the different results were attributable to court decisions that limited the Frye inquiry to whether an expert’s methodology was generally accepted and thus presumptively reliable. Unlike Daubert, the Frye standard did not allow courts to ask whether the expert applied the methodology in a reliable way. Under Frye, that question was for the jury to decide.

D.C. Abandons Frye Standard

In Motorola, the D.C. Court of Appeals recognized that the Daubert standard “in some respects relaxed traditional barriers to opinion testimony.” Opinions that are based on the reliable application of a reliable methodology to sufficient data are admissible even if the methodology has not been generally accepted. At the same time, the Daubert standard, unlike Frye, examines the expert’s application of the methodology. Under both Daubert and Frye, whether the expert’s conclusions are correct is for the jury to decide — but only if the judge allows the expert to testify.

The court recognized that Frye has been criticized for being “antiquated and out-of-step with modern science.” At the same time, the court noted that Daubert has been faulted “for producing inconsistent results, for making unqualified judges evaluate the work of scientists, and for invading the province of the jury.”

The court decided to adopt Daubert in both civil and criminal cases because it believed that Daubert, despite its flaws, will lead to “better decision-making by juries and trial judges alike.” Noting that the transition from Frye to Daubert will be difficult and that decisions in individual cases will probably be inconsistent, the court expressed confidence that trial courts would be guided by decisions of other jurisdictions that have adopted the widely-used Daubert standard. Finding definitive guidance might be challenging, however, given that appellate courts often disagree about the proper scope of a judge’s gatekeeping role under Daubert.

The court also cautioned that Daubert requires “a delicate touch” if judges are to avoid substituting their own judgment for conclusions that a jury should draw. The judge’s role as a gatekeeper is meant to prevent unsound evidence from reaching the jury. It is not meant to be a replacement for the adversary system of justice. The court noted that reliable applications of reliable methodologies can produce conflicting opinions, and emphasized that judges must take care not to evaluate the expert opinion itself. Only a jury can decide whether an opinion is credible.

Concurring Opinion Cites Doubtful Forensic Evidence

Judge Easterly’s notable concurring opinion urged judges applying Daubert to give special scrutiny to the opinions of forensic experts, even if the judges have grown used to admitting expert forensic opinions routinely under Frye. Judge Easterly called attention to expert methodologies that have been justly criticized as causing wrongful convictions. In particular, Judge Easterly called on trial court judges to pay special attention to the PCAST report and its recommendations for applying Daubert to dubious scientific methodologies that contribute to unreliable criminal convictions.

Photo Credit: Meade and Prettyman Courthouse, by AgnosticPreachersKid, CC BY-SA 3.0.

I voted stickers

Experts Testify in Pennsylvania Recount Litigation

Green Party presidential candidate Jill Stein asked for a recount in the three states with the closest election outcomes. The Wisconsin recount ended with President-elect Trump gaining an additional 131 votes. The Michigan recount was halted by a court ruling that Stein was not entitled to a recount since she had no hope of gaining enough votes to emerge as the victor.

While Stein sought a recount of paper ballots cast in Pennsylvania, most votes in that state are cast on direct-recording electronic (DRE) voting machines. Stein asked for a forensic analysis of the DRE machines to determine whether they had been hacked. A federal judge in Philadelphia denied that request after considering expert testimony from both sides, effectively ending Stein’s challenge to the election results.

Stein’s Claim

In 17 Pennsylvania counties, voters cast paper ballots that are counted by optical scanners. Since paper ballots can be preserved, the ballots can be recounted by hand.

In 54 Pennsylvania counties, voters cast their votes on DRE voting machines. Those machines preserve only a vote tally. There is no way to recount the votes if issues arise as to the accuracy of the tally.

Four Pennsylvania counties use a combination of optical scanners and DRE machines. Most Pennsylvania voters must therefore depend on the DRE machines if they want their votes to be counted.

Stein’s request was based on the concern that DRE machines are capable of being manipulated by hackers. Stein’s lawyer alleged that “DRE machines are easier to hack than an iPhone.” Even if DRE machines are easily hacked, whether the voting machines were actually hacked is a different question.

Stein’s suspicions were based in part on the CIA’s finding that “Russia intervened in the 2016 election to help Donald Trump win the presidency.” The CIA’s conclusion was based on Russia’s hacking of emails maintained by political organizations. Still, evidence that emails were hacked does not establish that voting machines were hacked.

Court’s Analysis

Following the reasoning of the state courts in Michigan, the federal court in Pennsylvania decided that Stein lacked “standing” to bring her lawsuit. Even if a recount were held, the court concluded, Stein would have no hope of winning the election. She therefore suffered no personal harm if the vote count was flawed. An allegation of personal harm is usually required before a party is entitled to bring a lawsuit.

Before bringing her federal lawsuit, Stein brought the same claim in Pennsylvania state courts. Those courts rejected her request. The federal judge decided it would be inappropriate to second-guess the state courts about election procedures that are determined by state law. In that regard, the judge’s reasoning departed from the Supreme Court’s Bush v. Gore decision, which declined to allow state courts to determine Florida’s election results in 2000.

Because the issues raised in the case are important, however, the judge analyzed the evidence to determine whether Stein’s claims had merit. The judge agreed that tampering with votes would impair the constitutional right to vote. To decide whether Stein had persuasive evidence of vote tampering, the judge considered the testimony of the expert witnesses.

Pennsylvania’s Expert

Dr. Michael Shamos has a Ph.D. in computer science as well as a law degree. He was “deeply involved in the creation and monitoring of Pennsylvania’s voting security procedures.” The judge agreed that Dr. Shamos is an expert in electronic voting, Pennsylvania’s election procedures, and computer science.

Based on Dr. Shamos’ testimony, the court concluded that votes in Pennsylvania are not tabulated on a single computer that is connected to the internet and thus susceptible to tampering. The judge also rejected the fear that “malware” might have been secretly installed on DRE voting machines or on vote tabulation machines, thus corrupting the results, based on Dr. Shamos’ opinion that the number of machines involved, and the security measures in place, would prevent any such hacking from occurring.

Dr. Shamos pointed out that the Russian hackers who tried to influence the election attacked email servers, while voting machines operate on different principles. He acknowledged the theoretical possibility that a DRE machine might be hacked despite the security measures in place to prevent that from happening, but dismissed the possibility of widespread hacking as bordering on the irrational.

Stein’s Expert

The court agreed that Stein’s expert, Dr. J. Alex Halderman, was qualified to testify about computer science, but determined that he “knew virtually nothing” about Pennsylvania’s security procedures or the practices of the state’s election officials. It is always a bad sign for a party when the court refers to the party’s “expert” in quotation marks.

Halderman admitted that he had no evidence of computer hacking and conceded that even if hacking occurred, it probably did not affect the election outcome. He relied in part on media reports of hacking in Illinois and Arizona, but the court discounted those concerns because they related to voter registration systems, not to hacks of off-line voting machines on election day.

Stein submitted the reports of four other experts, each of whom opined that DRE machines are vulnerable to hacking. The court discounted those opinions because they related to theoretical possibilities. In the absence of evidence that the machines were actually hacked, the court declined to delay certification of the election results while a forensic examination determined whether hacking occurred.

In the end, Stein raised important questions about the wisdom of voting on machines that do not permit a recount if the machines record inaccurate results, whether accidentally or due to outside interference. Since that question involves a policy judgment that is made by state legislatures, not by courts, and since Stein had no evidence that hacking occurred, the court gave more weight to Pennsylvania’s arguments (and the testimony of its expert) than to the concerns raised by Stein’s experts.

Washington State

Washington Conviction Reversed Due to Improper Impeachment of Expert

Concluding that the improper cross-examination of an expert witness probably contributed to Jimi James Hamilton’s conviction, the Washington Court of Appeals granted Hamilton a new trial. The conviction was Hamilton’s “third strike” under Washington law and therefore resulted in a life sentence.

Expert’s Testimony

Hamilton was charged with assaulting a corrections officer. His defense was based on the claim that he suffered from a mental disease or defect that diminished his capacity to form an intent to commit the crime. In support of that defense, Hamilton called Dr. Stuart Grassian as an expert witness.

Grassian’s testimony covered two issues. First, Grassian testified about the effect that solitary confinement has on prisoners, particularly when it is prolonged or repeated. In that regard, Grassian testified about the inadequate mental health services that are provided to prisoners in the Washington prison system.

Second, Grassian testified about mental illnesses from which Hamilton was suffering at the time he assaulted the prison guard. In particular, he opined that Hamilton suffered from a bipolar disorder with episodic periods of psychosis. He also testified about the impact those illnesses have on the decision-making process. Finally, he expressed the opinion that Hamilton was in a dissociative state at the time of the assault and lacked the capacity to form an intent to injure the guard.

Grassian formed his opinions about Hamilton’s mental health by interviewing Hamilton and his family members. Grassian also reviewed certain medical records, but he testified that the records were not well maintained and were not always coherent. He noted that certain opinions expressed in the records had no basis or were inadequately explained.

Cross-Examination of Expert

The prosecutor asked Grassian whether he relied on Hamilton’s medical records in forming his opinions. Grassian testified that he considered the records but did not rely upon them.

The prosecutor then used the records to impeach Grassian’s testimony. Over the objection of Hamilton’s attorney, the prosecutor repeatedly pointed to a medical opinion in the records that contradicted Grassian’s opinion, asked Grassian to read it aloud, asked Grassian to identify the professional who rendered that opinion, and asked Grassian to respond to it. The prosecutor also asked Grassian if he was more qualified than the professionals who rendered those opinions.

At least three of the professionals who prepared medical records expressed the opinion that Hamilton was faking a mental illness. Another expressed the opinion that he did not suffer from a bipolar disorder. Grassian testified that the opinions suggesting that Hamilton was faking a mental illness were not supported by facts that justified that opinion. Grassian also observed that some of the opinions were expressed several years before the assault for which Hamilton was on trial and might not reflect Hamilton’s current condition.

The defense objected that the prosecution was relying on hearsay statements made by medical experts who were not testifying, but the trial court ruled that the prosecutor was entitled to impeach Grassian with those statements. In the end, the jury rejected the diminished capacity defense and convicted Hamilton. He appealed.

Court of Appeals’ Decision

The Washington Court of Appeals reversed Hamilton’s conviction. The Court agreed with the defense that the medical records were inadmissible hearsay. The prosecutor’s use of the records to impeach Grassian’s opinions did not render those opinions admissible.

The Court of Appeals observed that the prosecution’s cross-examination tactics elicited the expert opinions stated in the medical records without calling the medical experts as witnesses. The Court noted that the medical records were never admitted into evidence and therefore could not be used as substantive evidence of Hamilton’s mental health.

The Court agreed with the prosecution that an expert witness may be impeached with information that the professional relied upon in forming an opinion, but held that Grassian could not be impeached with Hamilton’s medical records because Grassian did not rely upon them.

At trial, the prosecutor argued that Grassian should have relied upon the records. The Court of Appeals noted that the opinions only had value to Grassian if they were accurate. That meant that the prosecution wanted the jury to accept the truth of the opinions in the medical records. But statements made outside of court that are offered for their truth are hearsay, and the prosecution cited no exception to the hearsay rule that applied to expert opinions expressed in medical records when the records were not admitted as evidence. If the prosecutor wanted to impeach Grassian with medical opinions that Grassian did not rely upon, the prosecution was required to call its own expert.

Apparently realizing that the medical records were hearsay if the opinions in the records were represented as being true, the prosecution contended on appeal that the opinions in the records were not meant to be taken as true. The Court of Appeals concluded that untrue medical opinions have no value and are therefore not relevant. Either way, any opinions in the medical records were inadmissible.

Lessons Learned

Washington law, like the law of most states, allows an expert to be cross-examined about the basis of his or her opinion. And like the law of most states, Washington allows hearsay into evidence for the limited purpose of establishing the basis for an expert’s opinion.

The Hamilton decision should remind lawyers who use expert witnesses that they need to know exactly what facts an expert relied upon. Documents might be used against the expert at trial if the expert relied upon them, even if those documents would otherwise be hearsay. On the other hand, if the expert did not rely upon the documents, the lawyer will usually be entitled to object to cross-examination of the expert based on those documents because the documents themselves are hearsay.

The rule that the Court of Appeals relied upon is simple and clear: “Cross-examination that attempts to impeach by slipping in unrelied on opinions and conclusions without calling the experts to testify is improper.” Excluding medical opinions that are hearsay forces the other side to call its own expert, providing an opportunity to cross-examine that expert about the validity of his or her opinion.

Experts Give Opposing Testimony in Eureka Wrongful Death Case

Experts Give Opposing Testimony in Eureka Wrongful Death Case

The surviving relatives of Tommy McClain filed a wrongful death lawsuit against the City of Eureka, California. They alleged that an officer of the Eureka Police Department used unreasonable force against McClain and that the officer’s negligence resulted in McClain’s death.

Both sides relied on expert witnesses. Their conflicting testimony might explain a jury verdict that accepted one of the family’s claims while rejecting another.

McClain’s Confrontation with the Police

McClain’s parents sued Eureka after a police officer shot their 22-year-old son in September 2014. The officer fired seven shots, striking McClain in the forehead, chest, and buttocks. The officer said he shot McClain while McClain was reaching “with both hands” for a gun in his waistband. The weapon turned out to be an unloaded pellet gun.

McClain, his cousin, and two women returned home after celebrating his cousin’s birthday. They had been drinking. Unfortunately for McClain, police were staking out the side of the duplex adjacent to his residence. They believed that a criminal suspect was hiding in that unit.

The police watched as McClain confronted a man who parked nearby. The confrontation may have been related to a series of break-ins that had occurred in the neighborhood. After the man walked away, the officers became concerned that McClain might vandalize the vehicle. Not wanting to reveal their presence and thus jeopardize their surveillance, they asked a police car to cruise by, hoping that would dissuade McClain from behaving rashly.

The officers testified that McClain glared at the police car and “racked the slide” on his gun. Sergeant Brian Stephens then left his surveillance post, drew his gun, and “began yelling commands at McClain.” One of those commands was to lift his hands in the air, which he did.

Confusing Commands

McClain said “I didn’t do anything” and “You can’t search me.” The sergeant then told McClain to “get down” or “get down here.” The officer who had been in the car also began to yell commands.

McClain began to walk toward the sergeant. As he started to lower his hands, the sergeant ordered him to raise his hands again. McClain complied. When he lowered his hands again, the police officer who had been in the car shot him.

The evidence suggested there was considerable confusion about what McClain was being asked to do. On a videotape of the shooting, Stephens can be heard saying “Get down here right now.” Later he can be heard saying “Get down.” If McClain believed he was being told to “get down” — a common command on television shows about law enforcement — lowering his hands to place them on the ground would have been a natural response.

The officers testified that McClain did not appear to be lowering himself to the ground. Stephens testified that if he had wanted McClain on the ground, he would have ordered McClain to get on his knees and then to lie on his stomach. McClain, of course, had no reason to know about Stephens’ customary procedures.

Stephens testified he told McClain, “Don’t touch that gun or you’ll be shot.” Stephens could not explain why that statement does not appear on a video recording of the shooting.

Two officers who were hiding behind a fence did not leave their surveillance post. One of those officers testified that he witnessed the shooting. All three officers who were watching McClain testified that he reached for his gun. None of them claimed that he actually touched the gun. Another witness testified that McClain had his hands in plain sight at all times and never reached for the gun.

Expert Testimony

Roger Clark, a retired lieutenant for the Los Angeles County Sheriff’s Department, testified as an expert witness for the McClain family. Clark said he supervised a special team for five years that made 2,500 arrests and never had to fire a shot.

Clark told the jury that officers placed themselves at risk by failing to take cover before challenging McClain. If they had concealed themselves behind a car, they would have given themselves more time to assess the situation before deciding whether McClain was or was not complying with their commands.

In addition, Clark criticized the police for giving an ambiguous command (“Get down here right now”) and failing to clarify its meaning. Clark suggested that “Stay where you are. Don’t move. Keep your hands up” would have been consistent with standard police practices. According to Clark, police should never expect a suspect to walk with raised hands, but should take control of the situation by telling the suspect not to move at all.

Clark also said that McClain demonstrated his willingness to comply by walking toward the officers. When he lowered, raised, and lowered his hands, the officers should have understood that he was confused by their commands.

Alexander Jason, a crime-reconstruction expert, testified for the defense. He noted that one bullet went through McClain’s arm before it entered his chest, suggesting that McClain’s arm was down, not raised, at the time the shot was fired.

Don Cameron, an expert who trains police officers, also testified for the defense. He told the jury that it would not have been appropriate to wait after McClain began to lower his arms, because it only takes a second to draw a gun “and get a shot off.”

Cameron also testified that it was appropriate to continue shooting McClain while he was on the ground because the officers did not know whether he was dead. Until he was dead, there was still a chance that he might draw the gun.

Verdict

The jury returned a split verdict. Perhaps swayed by Cameron’s expert testimony, the jury decided that the police did not deliberately use excessive force when they shot McClain. At the same time, returning a verdict that was consistent with Clark’s expert testimony, the jury found that the officer who shot McClain was negligent.

The jury also found that McClain was equally negligent. Under California law, the $300,000 verdict is reduced by half to account for McClain’s contributory negligence.

Row houses in Philadelphia, PA

Experts Affix Blame in Philadelphia Building Collapse

Six people were killed and thirteen injured after the unbraced wall of a four-story building that was being demolished in Philadelphia collapsed, burying a neighboring single-story Salvation Army thrift store in rubble. One of the survivors was trapped for more than half a day before rescuers could reach her. Both of her legs were amputated at the hip.

Injury victims and relatives of the deceased sued a number of defendants who were allegedly responsible for the tragic event. A lengthy trial is well underway. Several expert witnesses have already testified for the plaintiffs and for the primary defendant.

Defendants in the Lawsuit

Defendants in the consolidated lawsuits include the demolition contractor, the excavator, and the architect who was hired to oversee the demolition. The primary defendant is real estate speculator Richard Basciano, whose company, STB Investments Corp., owned the building that was being razed. The plaintiffs also sued the Salvation Army for failing to protect employees and customers from a known danger.

Sean Benschop, the excavator, and Griffin Campbell, the contractor, were both convicted of involuntary manslaughter. Although they are defendants in the lawsuit, they probably have no way to pay any judgment that is entered against them. Another defendant, architect Plato Marinakos Jr., apparently had no insurance coverage that would pay any judgment that the jury might enter against him.

Claims and Defenses

The primary claim against Basciano is that he was negligent in hiring Marinakos and in failing to realize that Campbell was not qualified to handle the demolition. The plaintiffs have offered evidence that a key employee of Basiano knew that the demolition might endanger lives and property but allowed the project to continue.

The plaintiffs claim that Basciano’s aide warned the Salvation Army that its store might be placed at risk by the demolition. They allege that the Salvation Army ignored the warning because they thought it was a ploy by Basciano to induce the Salvation Army to swap its property for another Basciano property.

The Salvation Army rejected the proposed swap because it did not like the location of the property that Basciano offered. Bad blood became evident when Basciano’s property manager referred to the Salvation Army as “that half-baked charity.”

Basciano is basing his defense on expert testimony that the fault rests with the contractor who was responsible for the demolition and with the architect who was hired to oversee it.

Plaintiffs’ Forensic Construction Expert

The injury victims allege that Basciano and his property manager were negligent because neither Marinakos nor Campbell had prior experience bringing down a multistory commercial building. In support of that claim, the plaintiffs presented the expert testimony of Stephen A. Estrin, a former contractor who now analyzes building failures as a forensic construction consultant.

Estrin testified that Campbell was “totally incompetent and inexperienced.” Estrin also testified that Basciano and his property manager failed to adhere to industry standards when they did “no due-diligence research” before hiring Campbell. Estrin said that Basciano, relying solely on Marinakos’ recommendation, hired Campbell “despite the fact that Campbell had no city contractor’s license and had demolished just two burned-out rowhouses.”

Marinakos knew that Campbell was unlicensed. He also knew that Campbell had no insurance coverage for demolition, had no business account, and cashed his $25,000 deposit at a check cashing agency. Estrin told the jury that Basciano should have learned all of those facts and, had he done so, would have realized that Campbell lacked the credentials for a multistory demolition project. According to Estrin, Basciano cannot absolve himself of responsibility by blaming Marinakos for hiring an inept contractor.

Estrin testified for the plaintiffs before being cross-examined by lawyers for each of the defendants. He was on the witness stand for three full days.

Plaintiffs’ Retail Expert

The plaintiffs also presented the expert testimony of Alex J. Balian, the owner of a consulting firm specializing in retail management and store safety. He testified that the Salvation Army contributed to the casualties by failing to protect their customers from harm.

Balian faulted the Salvation Army for failing to investigate Basciano’s warnings of danger. He also noted that the store manager was aware of falling debris before the collapse and knew that no scaffolding had been installed to protect the store. Balian testified that the Salvation Army should have closed the store to protect its customers once the danger became apparent.

Store employees testified that they were never informed of the danger warnings that the Salvation Army received from Basciano’s employee. They also testified that the Salvation Army has a strict chain of command and that they were not authorized to close the store on their own initiative.

Defense Challenges

Lawyers for the defendants vigorously challenged the opinions of Balian and Estrin, claiming that they were rendering personal opinions as opposed to testifying about industry standards. In both cases, the judge ruled that the opinions were admissible as expert testimony.

Basciano’s Experts

Geoffrey N. Irvine testified for the defense as an expert in property management. He opined that Basciano and his property manager followed customary practices in the real estate industry by hiring Marinakos to monitor the project and to recommend the contractor to demolish the building.

Another expert testifying for Basciano, Philadelphia architect Robert H. Henderson, told the jury that Marinakos’ work on the project was “deceitful and leaning toward fraud.” Henderson’s testimony supported Basciano’s attempt to shift the blame for the building’s collapse to Marinakos. Henderson also suggested that Marinakos “rigged” the bids so that Campbell would get the demolition contract.

Basciano’s attempt to portray himself as the victim of inept or corrupt hired help might be undermined by evidence that his top aide sent several emails to the Salvation Army warning them that their building was in danger. The aide has testified that he was unaware of any actual danger but sent those emails as part of a strategy to induce the Salvation Army to swap its building for a different property.

The trial, one of the longest in Philadelphia history, has already taken weeks. The case will probably not reach the jury before January.

Bill Cosby

Bill Cosby Uses Memory Expert to Challenge Accusers

Defending against charges that he sexually assaulted Andrea Constand in 2004, Bill Cosby’s lawyers have asked the trial judge to decide whether thirteen other accusers who might testify against him are competent to give testimony. Cosby’s lawyer is relying upon an expert witness to suggest that the memories of the witnesses are unreliable.

Charges Against Cosby

Constand reported the alleged assault in 2005, about a year after she claimed that Cosby fondled her without her consent. The district attorney at that time decided that there was insufficient credible evidence to justify filing charges.

Eleven years later, a new district attorney decided to prosecute the case. Cosby’s lawyer contends that the charges are politically motivated in light of the prosecutor’s campaign pledge to prosecute Cosby if elected. The charges came after other women made well-publicized accusations against Cosby of inappropriate sexual conduct.

Cosby’s own admissions might be the strongest evidence against him. After Constand sued him, Cosby admitted in a deposition that he touched Constand in a sexual way after giving her Benadryl when she complained about stress. Cosby also admitted that on other occasions he gave Quaaludes to women before he had sex with them. Cosby maintains that all of the sexual encounters were consensual.

Proposed Prior Acts Testimony

The rules of evidence in most states prohibit a prosecutor from introducing evidence that a defendant committed crimes in the past to prove that the defendant is probably guilty of the charged crime. The rule against “bad acts” evidence is meant to shield a defendant from prejudicial attacks on his or her character that might persuade a jury that the defendant deserves punishment for being a bad person, even if it isn’t clear that the defendant committed the charged offense.

The prohibition against “bad acts” evidence is, however, riddled with exceptions. The prosecutors in Cosby’s case want to call thirteen women as witnesses to testify that Cosby drugged them and then sexually assaulted them. The prosecutors are relying on an exception that allows prior acts to be used to prove that a defendant committed a crime in such a specific way that it constitutes the defendant’s “signature.” That exception usually applies when the identification of the person who committed the alleged crime is doubtful, which isn’t the case here, but the prosecutors nevertheless want to bolster their proof that Cosby assaulted Constand by proving that he previously assaulted thirteen other women in the same way.

Proposed Expert Testimony

Cosby’s attorneys filed an unusual motion asking the court to determine the competency of the thirteen women to testify about acts that Cosby allegedly committed between 1967 and 1996. The defense notes that none of those allegations were reported to the police and most were never mentioned to anyone until the recent media flurry concerning the alleged assault of Constand.

The motion alleges that most of the women did not consider themselves to have been victims of an assault until recently. Many of them have no recollection of any sexual contact occurring. The defense contends that the court should determine that the women are not competent to testify because their memories are unreliable.

The motion is unusual in that witnesses are normally presumed to be competent to testify unless they are very young children or suffer from a mental infirmity. As long as a mentally healthy adult witness has the capacity to observe events, recall those observations, and describe them in court, whether the witness is giving accurate testimony is usually for the jury to decide.

According to the motion, Dr. Elizabeth Loftus, a psychologist who is a leading expert in the field of memory, has reviewed the evidence and concluded that the memories of the thirteen witnesses have been “tainted in the decades since their alleged assaults occurred.” She bases that opinion on:

  • The length of time that has passed since the alleged assaults, which increases the probability that their memories are inaccurate.
  • The likelihood that extensive media coverage has tainted or supplanted the memories of the women who are now accusing Cosby.
  • The likelihood that the close interaction of the women has tainted their memories, as each fed upon and adopted stories told by the others.
  • Evidence of suggestive questioning by police and the media that tainted the memories of the witnesses.
  • Changes in the stories the women have told, which suggests that their memories have changed over time and are therefore unreliable.

A legal memorandum accompanying the motion suggests that the accusers have been encouraged to recall assaults that never happened by a “media frenzy.” Ten of the women are represented by the same lawyer, who in many cases facilitated media attention to publicize their accusations.

Cross-Examination or Exclusion?

In most cases, the reliability of a memory is challenged at trial by cross-examining the witness. Attacks on the reliability of a memory can also be bolstered by calling an expert witness to testify at trial.

It would be unusual for a judge to exclude eyewitness testimony on the ground that an adult, mentally healthy witness is not competent to testify, but this is an unusual case. The fact that the alleged assaults occurred decades ago and only surfaced after extensive media coverage of Constand’s allegations might push this case into uncharted territory.

It could also be true that Cosby’s lawyers expect the motion to be denied, but are hoping for a pretrial hearing that will provide an early opportunity to cross-examine the witnesses. That would give them a chance to preview their testimony and to impeach them at trial if they deviated from their pretrial testimony.

At this point, the judge has not decided whether any or all of the thirteen witnesses will be excluded from testifying under the “bad acts” rule. If the judge decides their testimony is not relevant, the competency motion will become moot. If some or all of the witnesses are permitted to testify at trial, it seems clear that Cosby’s lawyers will rely on expert testimony to challenge the accuracy of their testimony.

Photo Credit: By The World Affairs Council of Philadelphia [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons