FBI BAU Supervisory Special Agent David Rossi is played by Joe Mantegna. Rossi was in early retirement until his return to the BAU. He has been searching for a killer who killed a mother and father in the same house as their three children, the oldest of whom found the bodies. He promised the children that he would catch their parents' killer. Rossi is haunted by the case until he finally solved it, twenty years later. Rossi replaced Jason Gideon (Mandy Patinkin). He is one of the most experienced profilers on the team, as well as having written a book on the subject.In 4x03 (Minimal Loss) he steps in as a hostage negotiator when Reid (Mathew Grey Gubler) and Prentiss (Paget Brewster) are held hostage.