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Comment by rtkwe | Hacker News Reader

I've read a couple books where the opposite was done. Intentionally dump huge amounts of DNA into the area to make any tracing pointless. One amusing and gross way was vacuuming bus seats for the material.

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The Unabomber retrieved pubic hair from a public restroom to plant as a false clue in one of his bombs[0].

0: https://www.chicagotribune.com/news/ct-xpm-1998-05-05-980505...

Reminds me of a scene in The Town - they were going to rob a bank, and they collected whole bags of hair from a barbershop floor, and spread it during the robbery.

Wouldn't that be quite useful for police?

They may be able to pinpoint a location - the barber where all the DNA matches go to have a haircut, and a time - soon after all those with majority DNA in the pile of hair went to the Barber's. Then they can analyse who was in the area around the time and find a person involved.

My thoughts exactly. The only true way is to appear to have never been there forensically, leave no sort of evidence. Security through obscurity only works in some instances.

There was a murder in Nebraska where crime scene was liberally cleaned with bleach to obliterate DNA evidence. Still no conviction despite a lot of circumstantial evidence. This was partially compounded by older DNA technology that destroyed the sample while processing it.

> This was partially compounded by older DNA technology that destroyed the sample while processing it.

Can you point to current DNA tech which doesn't destroy the sample while processing it?

For PCR you only need a super-tiny bit, then you can amplify it as much as you want. I guess you're still technically destroying that tiny bit, but it hardly makes a difference when you only need a few molecules.

That wouldn't actually do anything for DNA, cut hair doesn't actually contain any DNA at all the only way to get DNA from hair is if the follicle is still attached which wouldn't be true generally in a barber shop.

Not true anymore.

https://www.nytimes.com/2019/09/16/science/hair-dna-murder.h...

Keyboards are a great source of material. They accumulate no end of crap over time.

I wonder how often public library keyboards are cleaned, or the ones in university computer labs. When I was in college pulling all nighters in the computer lab I regularly saw the lab being cleaned, but I can't remember ever seeing the keyboards getting dusted off, let alone wiped off with disinfectants.

Go to two or three libraries in different corners of town, get what you want from the keyboards, and you should have quite the collection of DNA.

With the ease of travel I'd suggest go to libraries in different states or countries. Libraries close to major airports so that many people are likely to travel between them. (ie don't pick a city in the middle of nowhere just large enough to have a private airport)

Fun activity: turn the keyboard upside down over a sheet of newsprint or butcher paper, and tap the front corner gently on a hard surface.

The word for this type of accumulation of mixed biological material, crumbs, dandruff, eyelashes, and such is "kroonch".

Sometimes the best way to hide is in plain sight.

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