>How do investigators have any idea how it got there? They often can't be certain, and I'm sure somebody is in prison because they're DNA was in an inconvenien

>How do investigators have any idea how it got there? They often can't be certain, and I'm sure somebody is in prison because they're DNA was in an inconvenient place, but it's a far superior form of evidence than the other methods mentioned. Unless a crime is widely watched in person with supporting recordings and DNA evidence, it's basically impossible to be a 100% certain of what happened. That's why court only attempts to prove guilt beyond reasonable doubt.