[michjedi]

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.

[jdironman]

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.

[greedo]

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.

[inetknght]

> 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?

[brokenmachine]

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.