We will take a break this week from scaring you with science by....scaring you with science. The last thirty years have shown that DNA evidence can be used to convict (or exonerate) someone. It is now 2017. A new technology uses a DNA sample to pull "physical appearance and other information from DNA samples." The process is referred to as DNA phenotyping. Phenotyping attempts to predict likely hair color, eye color, skin, etc. That information is used to create a profile of a suspect (as in the photo below).
Then, if the police get a tip they follow around the suspected person until they can get a DNA sample (from a fork, spit, trash, etc.) and then run that DNA sample. And the odds that the sample will have a significance is high because we already know the person has the same eye color, hair color, etc. There are already examples of using this technology in Louisiana and California. For a discussion of some of the concerns related to phenotyping the ACLU has a section dedicated to the topic.