Williams v. United States

Judge Kate Easterly’s concurrence lays out the rationale for seeking a limitation on an examiner’s testimony. 

Focus on Judge Easterly’s concurrence which is highlighted in yellow. Feel free to skim (a) the facts, (b) the footnotes, and (c) even the court’s opinion - unless you want to see a powerful example of the damage that can be done by an unprepared defense attorney and how the standard of review inhibits progress in courts’ assessment of forensic evidence.

Judge Easterly is also one of my favorite writers, in part for writing clear, strong sentences like this one: “As matters currently stand, a certainty statement regarding toolmark pattern matching has the same probative value as the vision of a psychic: it reflects nothing more than the individual’s foundationless faith in what he believes to be true.”