Why CSI isn't like real life
People love CSI - if you have any doubt, look how many different CSI shows there are - Las Vegas, Miami and New York. I admit, I'm one of those people. Everyone who watches CSI knows how quickly they solve crimes, analyzing every piece of available evidence. Most shows include DNA evidence, where they quickly determine who has handled a piece of evidence.
It is possible to get DNA from an item even if there isn't blood. It's called "touch DNA", and tests epithelial cells that are discarded from our skin. As you can imagine, examining and testing every piece of evidence takes a lot of time, and money. While you can do it on TV, real life is different.
Criminal defendants and jurors also watch CSI. I can't tell you how many times I have had clients ask if an item was tested to see if there DNA was on it. Most of the time the answer is no, because DNA tests are generally only done in sexual assaults. Evidence in violent crimes may also be tested - generally it's blood that is left at the scene, or on an item of evidence. However, rarely will there be more than a few items tested.
The advent of touch DNA has caused concern not only over the lack of resources to test all the evidence, but also the lack of storage of space. The Integrity unit created by Texas Court of Criminal Appeals has expressed concern that storage capacity could be overwhelmed, both because of the amount of evidence, but also the longer wait times caused by the additional testing, which means evidence will have to be stored for longer periods of time.
On TV, every item of evidence is analyzed and tested. Crimes are often solved based on the minute or innocuous piece of evidence.. Don't expect the same in real life.
