The American Academy of Forensic Science Standards Board (ASB) has published ANSI/ASB Best Practice Recommendation 037, Guidelines for Opinions and Testimony in Forensic Toxicology, First Edition. This document delineates guidelines for best practices in forensic toxicology opinions and testimony, including human performance toxicology (e.g., driving under the influence of alcohol or drugs), postmortem forensic toxicology, court-ordered toxicology (e.g., probation and parole, drug courts, child services), and general forensic toxicology.
The American Academy of Forensic Sciences (AAFS) is working to develop best practice recommendations through a consensus process for each forensic discipline. Though the guidelines are non-binding, they do represent a deliberative process by which a group of forensic science practitioners, researchers, and court system stakeholders have developed recommendations on training standards, lab procedures, quality assurance, report writing, and testimony for each field.
The 2009 National Research Council Report, Strengthening Forensic Science: A Path Forward, emphasized the need for improving quality assurances, including continued standards-setting and enforcement. They wrote:
…Standards and best practices create a professional environment that allows organizations and professions to create quality systems, policies, and procedures and maintain autonomy from vested interest groups. Standards ensure desirable characteristics of services and techniques such as quality, reliability, efficiency, and consistency among practitioners. Typically standards are enforced through systems of accreditation and certification, wherein independent examiners and auditors test and audit the performance, policies, and procedures of both laboratories and service providers.
The Guidelines for Opinions and Testimony in Forensic Toxicology aim to “ensur[e] that proper toxicological testimony is allowed in legal matters by defining the general areas of forensic toxicology that are viewed as reliable by other experts in the field.”
The Guidelines specify that experts should provide both an analytical toxicology report and a separate report that conveys their opinions if they will offer an opinion on the interpretation of the toxicology findings (Section 4.1). In other words, under the Guidelines, an expert who will testify about the impairing effects of substances should provide that opinion in a written report, in addition to reporting the quantitative results that are typically provided in a Lab Report.
Additionally, the Guidelines specify that an opinion should clearly state any assumptions made; clearly state any known limitations of the opinion; cite references to support the opinion (and such references should be provided in the report or made available upon request); and be based on the totality of information available, including case history, observations, circumstances, and other relevant information, and not based solely on analytical results. (Section 4.3)
The Guidelines also define what are considered appropriate (Section 5.2) and inappropriate (Section 5.3) opinions and testimony by a toxicologist. These sections reiterate that opinions about impairment must be include consideration of the context of the case and not be based solely on a quantitative result. Also, words such as “scientific certainty” or “reasonable degree of scientific certainty” should not be used in testimony unless required by jurisdictional regulations.
All ASB publications can be downloaded for free from the Published Documents section of the ASB website.