Extracting DNA from the air – DNA evidence of human occupancy in indoor premises

I have always wondered why DNA is an accepted evidence. It's so easy to contaminate a crime scene or bring someone else hair, skin cells, etc by mistake.

In theory, you could do a "perfect crime" by going to a seedy part of town, picking up a dropped cigarette butt, and leaving it at the crime scene, framing someone else.

In reality, criminals are angry, frightened, in a rush, high or stupid, and they make the most elementary mistakes, so DNA and fingerprints work just fine almost all the time. In like 99% of cases there's not much doubt about who did it, the main thing is to have a watertight case against them when they deny it.

>so DNA and fingerprints work just fine almost all the time.

except for all of those innocent folks that have had their lives ruined by that 'almost all the time' caveat, it's great!

here's a report[0] that says something like 80% + of criminal forensic work has major mistakes within it.

[0]: https://www.criminallegalnews.org/news/2024/may/15/report-fi...