In the Louisville police cold case squad, two veteran homicide investigators pore over files that go back decades, says the Louisville Courier-Journal. They analyze old evidence with the newest technology and sometimes re-interview witnesses, searching for the elusive incriminating clue that can bring a perpetrator to justice long overdue. The squad is working on 40 cases. “It pays sometimes to think outside the box,” says detective Larry Carroll. “There might be a name that stands out now that didn’t then. We might even detect a pattern where several people have been killed, and suddenly there’s a common thread.” One success involved a wanted man who in 2002 unwittingly supplied a fingerprint and his own damning DNA sample on an envelope flap he licked, sealing a letter to detectives bragging that he’d never be caught.
The Louisville unit, formed in 2000, echoed a nationwide trend. America’s first cold-case squad was organized by the Miami-Dade County Police Department in the early 1980s. Seattle created its cold-case squad in 2000, and last year departments in Arlington, Texas, and Portland, Ore., started theirs.