The poster you're replying to is referring to the misuse of statistics, essentially. Think about it this way: it's not amazing that someone wins the lottery. It

The poster you're replying to is referring to the misuse of statistics, essentially. Think about it this way: it's not amazing that someone wins the lottery. It'd be pretty amazing if a specific person won the lottery (statistically speaking). Here's where DNA evidence shines: through other means you have a suspect or a short list of suspects and you use DNA evidence from the crime scene to eliminate suspects or concur with existing evidence. Here's where DNA evidence is abused: if you take essentially a "hash" of DNA and look for matches to that same hash. There are enough people that you're likely to find unrelated hits (collisions, essentially) and then law enforcement puts the onus of proving their innocence on those people. This works particularly badly for the poor who are less likely to have credit card receipts and other evidence that might otherwise constitute an alibi. Don't believe me? Consider [1] for issues in fingerprint matching. DNA databases are getting sufficiently large that adventitious matches are much more common than you might think [2]. I believe there's been at least one murder case in the US where searching the fingerprint database brought up a completely unrelated person who had the exact same fingerprint (based on the markers) but I can't find a reference to it now. tl;dr Fingerprints and DNA are good for eliminating or indicting someone you otherwise have legal cause to suspect and shouldn't be used as a blanket scan. [1] https://theconversation.com/fingerprinting-to-solve-crimes-not-as-robust-as-you-think-85534 https://theconversation.com/fingerprinting-to-solve-crimes-n... [2] https://www.theguardian.com/science/2004/sep/09/sciencenews.crime https://www.theguardian.com/science/2004/sep/09/sciencenews....