Who knew there was such a thing.
I was looking through some of the mounds of sniper articles out there and stumble across this interesting article on Time’s web site. On the second page, the humor started. Following is a snippet taken directly from Time, which means it’s copyright them, etc.
“For example, one of the jobs criminal investigators routinely perform is testing for gunpowder on suspects’ hands. In the past, this was a surprisingly low-tech chore, involving melting a glob of paraffin in a pot and painting it onto the fingers and hands. The wax was then peeled off and treated with chemicals that react to gunpowder traces. If the chemicals turned up positive, you had your shooter—unless, of course, the chemicals were reacting with urine, bleach or fertilizer, which had a nasty habit of yielding identical results.
Today most forensics labs that conduct the test rely instead on scanning electron microscopes. Just touch a bit of tape to a suspect’s hands, place it under the scope and hit it with a stream of electrons. The elements in gunpowder give off distinct X-ray signatures, and if they are there, the electron beam will spot them. The drawback? ‘You don’t get to see the terror on people’s faces when you pour hot paraffin on their hands,’ says Fischer. ‘I think it encouraged some people to confess.’ ” (my bold)