In the police world, a case is either 'hot' or 'cold'. For a murder to be 'hot', one must have a warm body, a suspect, opportunity, motive, evidence and the will to prosecute. Without these, the file is passed down to the 'Cold Squad'. This crack team of detectives take unsolved crimes, and using the latest advances in technology such as DNA testing, computer matching, and their own unique blend of expertise, track down the criminals who thought they had got away with murder.