Zoe's Reprise

Zoe's Reprise is the fifteenth episode of season 4 of Criminal Minds.

Summary
A young Criminology student, Zoe, is murdered at a previous crime scene after suggesting to Rossi that it, and other seemingly unrelated murders may actually be related. The team investigates and learns that Zoe may have been correct, and that these murders-including hers-are the work of a copycat serial killer, who is experimenting with the MOs of past killers in order to find his own style.