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

(www.nature.com)
248 points punnerud | 1 comments | 15 Mar 25 18:38 UTC | HN request time: 0.249s | source
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h1fra ◴[18 Mar 25 09:13 UTC] No.43397159[source]▶
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.
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rwmj ◴[18 Mar 25 09:39 UTC] No.43397344[source]▶
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.

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1. abecedarius ◴[18 Mar 25 14:09 UTC] No.43399611[source]▶
When we're talking about quality of evidence, saying "in reality" is skipping to your conclusion. Are smart careful people rare among known criminals? Well, yes. What would you expect to see? https://www.econlib.org/archives/2015/02/the_wittgenstei.htm...