Some police now use special DNA guns to "tag" criminals, such as rioters or protesters. Meanwhile, regular folks in Sweden can buy a DNA spray to cover a perpetrator in a later-matchable DNA. But that's all using pre-created DNA. Most times, police are just looking for DNA inadvertently left by someone. And while in those CSI episodes, perpetrators' photos and DNA are somehow always in some database, that’s not the case in the non-scripted and televised world, so DNA can often be of little use.

Genetics and technology are quickly reaching a point where we could create fairly accurate images of faces based simply off DNA, according a study published on March 20. At present, we’re able to figure out a few things from DNA, such as racial background and, at times, hair color. These things are useful, but certainly aren't enough to go on when seeing a suspect. In 2012, a professor at Erasmus University Medical Center in Rotterdam found five genetic variants that can give us insight into the shape of someone's face. That isn't quite enough to paint a picture of someone’s face based solely on DNA, but it’s a heck of a lot further than we were in 2011.