Although you have already replied to the DNA comment, one must take care with bureaucracies always. They will drag on with some preconception and the citizen always loses.
> In formal settings, the problem will be taken care of
Forensic evidence has been and still is systematically abused:
> * a 2002 FBI re-examination of microscopic hair comparisons the agency’s scientists had performed in criminal cases, in which DNA testing revealed that 11 percent of hair samples found to match microscopically actually came from different individuals;
> * a 2004 National Research Council report, commissioned by the FBI, on bullet-lead evidence, which found that there was insufficient research and data to support drawing a definitive connection between two bullets based on compositional similarity of the lead they contain;
> * a 2005 report of an international committee established by the FBI to review the use of latent fingerprint evidence in the case of a terrorist bombing in Spain, in which the committee found that “confirmation bias”—the inclination to confirm a suspicion based on other grounds—contributed to a misidentification and improper detention; and
> * studies reported in 2009 and 2010 on bitemark evidence, which found that current procedures for comparing bitemarks are unable to reliably exclude or include a suspect as a potential biter.
> Beyond these kinds of shortfalls with respect to “reliable methods” in forensic feature-comparison disciplines, reviews have found that expert witnesses have often overstated the probative value of their evidence, going far beyond what the relevant science can justify.
The bigger problem is informal settings. Propaganda, for one.