Anyone arrested for a serious crime can now get swabbed for DNA.
A recent ruling by the Supreme Court allows police to do it.
Cameron County Sheriff Omar Lucio said he's glad the supreme court has allowed for the testing.
He said in Cameron County they haven't used that particular method very much, but he thinks more police departments will start DNA swabbing.
Sheriff Lucio said they've had about six cold cases.
He remembers a case in 2005 when he was re-elected and a homicide dating back to 1995.
Sheriff Lucio said for some reason these cases were not completed or they didn't have sufficient evidence.
But as they were sifting through evidence, they found one key peace that solved the puzzle.
The officer had picked up a cigarette, Sheriff Lucio said. What we call a cigarette bud and we kept it in the evidence going through the evidence and we realized that we had something here and that DNA could be the answer to that particular case."
The evidence was sent out for analysis to the Texas Department of Public Safety.
By getting a sample of his DNA, they were able to make a positive match with the suspect.
He pleaded guilty and was sentenced to 20 years in prison.