Category Archives: Experts

New Benchbook Chapter on Expert Testimony

School of Government Professor Jessie Smith has drafted a new chapter on Expert Testimony for the NC Superior Court Judge’s Benchbook. I’ve already heard one judge say from the bench that he had it open as he was considering a 702 challenge to expert testimony. Because this is a resource that judges look to, defenders should be familiar with it when preparing for 702/Daubert hearings regarding expert testimony.

Professor Smith references the President’s Council of Advisors on Science and Technology report, Forensic Science in the Courts: Ensuring Scientific Validity of Feature Comparison Methods, (hereinafter, PCAST Report) (available for free download here). The chapter uses the PCAST Report and other resources to note areas where there are questions about the reliability of certain types of forensic evidence. I have posted about the 2016 PCAST Report here, and I hope its being referenced in the Benchbook will lead to judges and other court actors taking a look at that landmark report on forensic evidence.

A significant portion of the chapter looks at each type of forensic evidence and summarizes the existing case law and mentions additional relevant considerations. Other sections of the chapter that defenders will want to take note of are the section on statements and terminology that the PCAST Report says are not scientifically valid (p. 54), the section on whether judges declaring a witness to be an expert in the presence of the jury inadvertently puts the court’s stamp of authority on a witness’s opinion (p. 22), and the discussion on best practices regarding the procedure for holding a 702/Daubert hearing (p. 21-22).



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Language Matters: USDOJ’s Reporting Language and Testimony Guidelines

Forensic scientists are tasked with the job of explaining often complex scientific data to judges, jurors, and attorneys who may have little understanding of the science underlying the forensic analysis in a case.

Revelations in recent years that hair analysts provided testimony that had no scientific validity has highlighted the importance of using correct language to convey information about forensic analysis and its limitations. Several wrongful convictions have been overturned based on faulty testimony about hair evidence and a massive review of hair cases is ongoing.

In an effort to improve expert testimony, the U.S. Department of Justice has released proposed guidelines called the Uniform Language for Testimony and Reports. These guidelines, once finalized, will apply to all USDOJ personnel who issue reports or provide expert forensic testimony, and they will probably be viewed as best practices for the entire forensic community. The guidelines are currently accessible at, with the public comment section running through July 8, 2016.

Attorneys should be aware of these guidelines and be prepared to object to any lab report language or testimony that does not comply. For example, the Uniform Language for Testimony and Reports for the Forensic Latent Print Discipline provides the following guidance on what experts cannot say about their evidence: (1) they cannot state that two prints originate from the same source to the absolute exclusion of all other sources; (2) they cannot state that there is any statistical level of certainty attributed to their determination; (3) they cannot testify that their science is infallible. Similarly, for the testing of bodily fluids, analysts may not state or imply that a level of numerical certainty is calculated to support the identification of blood or semen (i.e., they cannot say they are 95 per cent confident that the stain contained blood or there is a one in a hundred chance that the stain was something other than semen) and may not state or imply that the methods used in performing serological examinations have error rates of zero or that they are infallible. For drug analysis, the guidelines specify that when no sampling plan was used and no reasonable assumption of homogeneity of an item was determined, the examiner may not report or state an opinion that the conclusions apply to the entirety of an item (or a percentage of the item). This limitation is important in pill cases where only one pill is tested.

So, if you have any suggestions about appropriate limitations for expert testimony, or the language they should use in reports, please take the time to provide feedback on these documents.

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Vetting Experts – A Wake-Up Call

A recent meeting with a supposed forensic psychology expert reminded me of the importance of attorneys always vetting their own experts. This individual was referred to me by another trusted expert. After our initial meeting, I started looking in to his credentials and quickly learned that he did not have a Ph.D. and was not licensed to practice in North Carolina. His claim that he testified in a high-profile case was untrue, and he did not have the work experience that he claimed to have.

It only took a few phone calls to uncover this information, and it was a reminder of how important it is to verify the credentials of experts. Even if an expert comes recommended by a trusted attorney or expert, the attorney hiring the expert must vet the expert herself. Some attorneys think that experts listed in the IDS Database of Experts are approved by IDS. This is not the case. Indigent Defense Services simply does not have the staff to vet the hundreds of experts who are included in the database and continue to research these experts to monitor for any issues that may arise.

Below are a few steps that attorneys can take to verify the credentials of experts. Attorneys should discuss the questions below with the expert and verify the information independently. Additional information on researching experts is available on the IDS Forensic Website.

  1. Licensure: Is the expert licensed to practice in NC? By what board? When did he or she become licensed and are there any disciplinary issues currently or recently affecting his or her license? Attorneys can verify licensure of psychologists (NC Psychology Board) and medical doctors (NC Medical Board) online.
  2. Board Certification: Is the expert board certified as a specialist in the field? How long has he or she been certified? If certification, proficiency testing, or other exams have been attempted, what were the results? This website can be used to check to see whether an medical doctor is certified in any specialty.
  3. Education and publications: Does the expert have the educational degree they claim to have? Some universities will provide that information – others will refer attorneys to the National Student Clearinghouse. An expert’s name can be searched in PubMed to find a list of biomedical literature publications.
  4. Forensic training: what mentoring/supervision has the expert had regarding forensic work? Attorneys can call these mentors or supervisors to verify this information and learn more about the expert.
  5. Testimony: How many times has the expert testified as an expert witness? Has a court ever found the expert was not qualified to testify or limited the testimony? A search of LexisNexis or WestLaw will identify any published opinions addressing the expert’s testimony.
  6. Other issues: Is there any personal or professional information that could be used as impeachment material or to disqualify the expert? Does the expert have any criminal convictions or pending criminal charges, including DWI cases, in any state?

In addition to answering these questions, attorneys may need to verify additional information listed on the expert’s CV. Finally, attorneys may want to review transcripts of the expert’s prior testimony. Attorneys can contact Sarah Rackley Olson for assistance in locating such transcripts.

While following these step will not guarantee that the expert has nothing to hide, these are the minimum steps that an attorney should take to ferret out whether the expert is being forthcoming about his or her qualifications. This type of research also can be helpful in identifying weaknesses in the qualifications of the state’s expert witnesses.


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Does a psychology expert need to be licensed in NC?

Attorneys may need the services of a psychologist to evaluate whether a client is competent to stand trial, to present evidence regarding a mental health defense or mitigation, or to perform other psychological testing of a client. Attorneys have asked me whether a psychologist needs to be licensed in NC to perform these services. I’ll attempt to answer below.

In a capital case, if the defense seeks to establish that the defendant is mentally retarded, NC General Statutes require that the IQ test be administered by a licensed psychiatrist or psychologist. N.C. Gen. Stat. § 15A-2005 (2014).

For other types of psychological services, the N.C. Psychology Practice Act sets standards for practicing psychology in North Carolina, and includes requirements for education, examination, supervision, and licensing. N.C. Gen. Stat. § 90-270 (2013). The Act allows certain types of consultation and testimony to be provided by a non-licensed psychologist. For example, if testimony is needed regarding the characteristics of a particular mental health disorder, this type of general information could be provided by a non-licensed psychologist. N.C. Gen. Stat. § 90-270.4(a). However, if the case requires that the expert conduct any testing or evaluation of the defendant, the expert would need to be a licensed psychologist because this work would involve the provision of psychological services to an individual.

The Act includes an exemption that allows for psychologists licensed outside of North Carolina to practice within the state. Psychologists licensed in other states can apply for an exemption to practice psychology, including the provision of health services, in North Carolina for either five or 30 days in any calendar year. N.C. Gen. Stat. § 90-270.4(f). The psychologist should contact the North Carolina Psychology Board to apply for this limited right to practice in North Carolina.

Though there may be limited circumstances in which a psychologist who does not have a license may provide expert services in North Carolina, it is advisable for attorneys to use a licensed psychologist or to consult with the NC Psychology Board to determine whether the use of a non-licensed psychologist is permissible. Attorneys can visit the NC Psychology Board’s website to verify whether a psychologist has an active license in North Carolina and whether there are any disciplinary issues currently or recently impacting their licensure.


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Draft Policy Recommendations by the National Commission on Forensic Science

The National Commission on Forensic Science has released six documents for public review and comment. The Commission’s recommendations, if adopted, will be recommendations to the Attorney General of the United States. However, they may become recognized as best practices for practitioners and courts dealing with forensic evidence.

Attorneys or others who wish to comment on these recommendations can follow the procedures here. Attorneys may be particularly interested in the recommendations on discovery and expert testimony.

The Draft Policy Recommendation on Discovery discusses the importance of bench notes, as well as access to laboratory testing protocols, quality assurance procedures, accreditation and audit reports, proficiency testing results, and internal validation studies. Attorneys can review this post to understand which documents the NC State Crime Laboratory provides through discovery. Other labs or forensic examiners in the state might not provide all of these items. The recommendation compares the discovery provided in civil cases with the unsupported conclusory reports sometimes provided in criminal cases that summarize the results of an unidentified test conducted by an anonymous technician. The recommendations may provide attorneys with additional arguments for access to complete lab reports. The recommendation on discovery also contains important information about the preservation, consumption, and retesting of evidence.

The Draft Policy on Expert Testimony contains important information about limitations that should be placed on expert testimony, including testimony about zero error rates, the statistical basis for a technique, and the use of the word “scientific” in describing non-scientific analysis. The recommendation also calls on courts to not declare a witness to be an “expert witness” in front of the jury because the court’s acknowledgement that an witness is an “expert” may unduly influence the jury’s opinion about that witness’s testimony.

The draft policy recommendations are available here:

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Cognitive Bias and Forensic Anthropology

A study looking at how the conclusions of forensic anthropologists may be influenced by extraneous information highlights the importance of protecting all scientists from potentially biasing information.

Forensic anthropologists determine the gender, national origin, and age of a person at the time of death. In some cases this determination must be based solely on skeletal remains. A recent study introduced extraneous information to the scientists when remains were submitted for scientific analysis and found that background information can bias a scientist’s conclusions and result in mis-identifications across the board.

In this study, three test groups were assembled to analyze the remains of a nineteenth century female skeleton with strikingly neutral, or “ambiguous,” features which could allow a conclusion of either sex. An ambiguous environment is one that creates the greatest potential for cognitive bias. Cognitive bias occurs when contextual information influences a person’s thought process and may lead to inaccurate judgment. In this case, scientists relied on information that was submitted with the evidence, causing them to make conclusions validating or complementing the extraneous information.

Two of the three groups were given DNA profiles in addition to skeletal remains. The first group’s DNA profile indicated the skeletal remains belonged to a Caucasian male between 25-30 years of age. The second group was given a DNA profile indicating the same skeleton was an Asian female between 50-55 years of age. The third group, the control group, was given no supplementary information. Each scientist, ranging from master’s degree students to practicing PhDs in anthropology, was given up to an hour to examine the remains and make conclusions. In the first group, 72% concluded the remains were male and 100% of examiners in the second group concluded the remains were female. In the control group 31% of examiners concluded the remains were male and 69% concluded female.

Regarding ancestry, 100% of group one (who were told the skeleton was Caucasian) and 100% of the control group (who were given no extra information) decided that the skeleton was Caucasian. In group two, where the scientists were told the skeleton was of Asian ancestry, 50% concluded the skeleton was of Asian descent and 50% concluded Caucasian. The study attributes the bias in both group one and the control group to cognitive bias and bias generated from ancestrally-common characteristics described in anthropological textbooks.

This study showed that age at time of death is the least affected category by cognitive bias. Anthropologists in each group reached conclusions about age independent of the supplied information.

This study shows how biasing contextual information can affect a scientist’s ability to be impartial. The accuracy and credibility of a scientist’s conclusions depends upon blinding the scientist to any information that can be consciously or unconsciously biasing. Attorneys may be interested in reading similar studies that have looked at how contextual information can bias examiners in the fields of blood spatter interpretation, fingerprint comparison, and DNA interpretation.


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Post on new fees for forensic expert testimony

School of Government Professor Jessica Smith authored an informative post entitled Imposing Fees for Forensic Expert Testimony — Is It Constitutional? on the North Carolina Criminal Law blog this morning. The post looks at a new $600 fee imposed on defendants when a State Crime Lab or a local crime lab analyst testifies at trial regarding forensic analysis. Jessica Smith discusses whether this new fee is constitutional as applied to defendants exercising their Sixth Amendment confrontation right that was newly declared in Melendez-Diaz v. Massachusetts. Anyone considering challenging the imposition of this fee should take a look at the arguments for and against its constitutionality in this post.


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