I read a story where an assailant carried a spray bottle of “Soccer Stadium” and spread the DNA of 50,000 random people around the crime scene. I’ve never looked at DNA forensics the same way since.
The book never mentioned how the DNA was collected, or where he obtained it. I suppose a couple of crooked hospital lab workers would have daily access to thousands of samples, and a criminal enterprise would be able to quickly PCR up a vat full. You probably wouldn’t want to be caught with a bottle of it, though.
