Under the Gun

Also available on the NBC app

Casey agrees to participate in a sting operation to catch Hallie's murderer, but when the plan goes haywire, Casey finds himself in the clutches of a ruthless killer.

Appearing:Jesse Spencer
Tags: casey, Train, chase, murderer, Sting, police, chicago pd, el train, gun, gunpoint, hostage, voight, Antonio, pursuit
S1 E234 minExcerptDramaPrimetime