DNA also just ends up all over the place for innocent reasons. If someone gets murdered in a rental car that I rented last month, chances are my dna will be there. DNA evidence often struggles when it comes to temporality, as it can tell you who and where, but it can’t tell you when the evidence was placed there.

Historically there have been some pretty bad abuses in court over the accuracy and reliability of dna evidence, with some convictions that had to later get overturned.