CNN Anderson Cooper 360 May 23, 2015 00:18:00
For more dna from the lab and the courtroom, we are joined by the department at the john j college here in new york. also the defense attorney. >> the chances of this guy being on the databases, how does someone get on that from a prior crime? >> the database is called codis. it has three levels. a local database and state databases which the states keep and the national database. at the state level, they are eligible for the database. the point is there an awful lot of people that are convicted felons on this system. almost 12 million people. see this if somebody commits a crime and leaves dn...