Prof. Roger Park of Hastings has published a very thoughtful reply to people (e.g., Prof. D. Michael Risinger) who argue that "forensic document examiners" aren't very good at determining whether two separate signatures were or were not made by the same person. See R. Park, "Signature Identification in the Light of Science and Experience," 59 Hastings Law Journal 1101 (2008).
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consulting on investigation strategy and the law of evidence