CODIS is the Combined DNA Index System, and theoretically, a person convicted of a felony has a sample taken and then the DNA is entered into state and national databases to compare against past and future crimes. I say theoretically, because in several instances, that DNA isn’t taken, at least in a timely manner and DNA from crime scenes sits without a match for years, when the suspect is in prison the whole time. It’s a problem in Washington State and nationally. I bumped into this while investigating the Shannon Harps murder, of which I wrote in my book. Harps’ killer, James Williams served ten years in prison for shooting a man. His DNA was collected, but never processed and entered into CODIS. Fortunately we collected it and submitted it to the lab, getting a match with DNA found on the murder weapon, but had we not come across Williams, that case might still be unsolved; unessisarily so.
Seth Augunstein is a reporter for Forensics Magazine. He wrote a great article about that issue last summer.
You can find that article here.