Hacker News Reader

Comment by jrs95 | Hacker News Reader

Were the ones they've identified repeat offenders or something? I was under the impression that a relatively small % of the population had their DNA in a database.

View on HN

You don't have to be in a database before for your DNA in one rape kit to be identified as being (nearly certainly) from the same person as your DNA in 9+ other rape kits.

The article does say they have gone on to arrest 127 people, so presumably they were also able to identify the perpetrator from the DNA (or the testimony of the victim).

Right, but that doesn't mean the other 670+ of the 800 serial rapists were identified against another database or way of identifying the individual besides “the same individual as indicated in these other rape kits”.

Quite possibly some of the rape kits also included files where the victim said “Joe did it” but wasn’t believed at the time. Now when Joe’s DNA is found in a bunch of other rape kits where the perpetrator was unidentified, the picture of our friend Joe gets a bit clearer...

Yes, "serial" means "repeat" in this context.

Specifically, TFA said that they defined "serial rapist" as those who raped 10-15 times without being caught.

The boingboing article says that, but the actual source (Detroit Free Press) article that underlies it makes it clear that the threshold is lower and the boingboing write-up is misstating the facts:

“Of our set of 817 ... over 50 of them have 10 to 15 hits apiece.”

https://www.freep.com/story/opinion/columnists/nancy-kaffer/...

Thank you for that correction, that's indeed very different and it's a shame the reporting is so sloppy

If you are suspected of a crime in which DNA is relevant and set foot in a police station it's not unheard of for them to ask you if you'd like a water in case you drink from it and leave the bottle in the trash.

Is there any documented case of this?

Here's one where an armrest of a chair was swabbed at the police station.

https://www.policeone.com/legal/articles/8691418-How-surrept...

I watch a lot of true stories about how crimes are solved and this does happen though not a lot.

Sometimes police tail a suspect and wait until they leave their DNA somewhere, like if they drop a cigarette butt on the ground or if they throw a drink cup away.

Reply on news.ycombinator.com