You watch the crime shows on TV and they use DNA databases all the time to catch the bad guys. In real life – police do the same thing. Maryland State Police say their DNA database, which was established in 1994, is an invaluable tool to help reduce crime, apprehend criminals and exonerate the innocent. Officials say their database has now recorded 6000 positive comparisons. That’s when DNA from a crime victim or scene is matched with either a known offender sample or from another crime scene that’s on file in Maryland’s DNA database – or CODIS – the national database.