<P> In the season ten episode `` Nelson 's Sparrow '' , Gideon was murdered off - screen , having been shot dead at a close range by a serial killer named Donnie Mallick ( Arye Gross ) , which prompts the BAU team to investigate Gideon 's murder . During the flashbacks focusing on a young version of him for the episode which show him working at the BAU in 1978 , he is played by Ben Savage . </P>
which episode does gideon die in criminal minds
Nelson 's Sparrow