All my forensic casework has seen attorneys asking experts about their  “training and experience” relationship to rendered opinions. The AAAS (The American Association for the Advancement of Science” (The World’s Largest)  calls out this permissive aspect of qualifying an expert’s “science”  to be …………

“There is no scientific basis for estimating the number of individuals who might have a particular pattern of features; therefore, there is no scientific basis on which an examiner might form an expectation of whether an arrangement comes from the same source,” said Holt. “The proposed language fails to acknowledge the uncertainty that exists regarding the rarity of particular fingerprint patterns. Any expectations that an examiner asserts necessarily rest on speculation, rather than scientific evidence.”

The USDOJ “new” forensic testimony guides includes this out-dated excuse for real-life accuracy testing in the area of latent fingerprint comparisons. This is an excellent example of scientists shaking their heads regarding how behind the times the US Criminal Justice system thresholds are for scientific “facts” cloaked as “forensics.”

What is impressive: is the AAAS consistent oversight in the areas of forensics. They make the AAFS look like a bunch of itinerant practitioners.

https://www.aaas.org/news/aaas-asks-justice-department-modify-fingerprint-reporting-guidelines

Previous Forensic and Law blog on this subject.