S4·E11 Street Bait

After the third in a series of murders on attractive young blonde women, Stacy goes undercover to work as a salesgirl at a shopping mall store where each of the girls had worked, to act as bait to try and lure out the killer. With Stacy wired up, Hooker, Corrigan and Romano keep tabs on her until the killer makes himself apparent, but Hooker is concerned when the gun used in the murders suggests the killer to be a cop, and all indications point to the store's security officer being the culprit. But the operation puts Stacy in a dangerous position.