PCAST Report
Definition
The 2016 report by the US President's Council of Advisors on Science and Technology that evaluated the foundational validity and validity as applied of several forensic feature-comparison disciplines. It concluded that DNA analysis, bite mark analysis, latent fingerprints, firearms, footwear, and hair required further empirical studies to establish error rates.
- Publisher
- US President's Council of Advisors on Science and Technology
- Year
- 2016
- Disciplines reviewed
- DNA, bite marks, latent fingerprints, firearms, footwear, hair
- Main conclusion
- Further empirical error-rate studies needed for several disciplines
Common questions
Did the PCAST report find all six disciplines equally lacking?+
No. DNA analysis of single-source samples was found to have well-established validity, while methods like bite mark analysis were found to lack foundational validity altogether. The report graded disciplines differently rather than issuing one blanket verdict.
How is the PCAST report typically used in a courtroom challenge to expert testimony?+
Defence counsel commonly cite it during Daubert or Frye admissibility hearings to argue that a proposed comparison method lacks an adequate error-rate foundation, prompting judges to scrutinise or limit how confidently an examiner may state a match conclusion.
Related terms
- Foundational Validity
- The requirement, articulated in the 2009 US National Academy of Sciences report and taken up by courts and reform bodies, that a...
- Likelihood Ratio (LR)
- The ratio of two conditional probabilities: the probability of the observed evidence given the prosecution's hypothesis (same source), divided by the probability...
- Match Probability
- The probability that a randomly selected person or object from the relevant population would produce evidence as similar as the crime-scene sample,...
- Rarity Estimate
- A numerical statement of how uncommon a particular feature combination is in a reference population. Derived from frequency databases or empirical studies....
- Refractive Index (RI)
- A physical property of glass measuring how much light bends as it passes through. RI is the primary discriminating characteristic used in...