S6, E16: When a body is discovered stuffed in a working chimney of a residential home, CSI discover the body had been burned previously to be dumped at the house, and that the ID of the body is the son of the homeowner. During the processing of the home, Catherine and Warrick realize this is the same address of an unsolved homicide of a young female teenager from a year ago, and are able to re-open the investigation.