Episode 504, "Eyes In"
SEASON 3, EPISODE 316 - In the wake of a shooting spree, SRU’s actions and judgments are put under a microscope. In an all flashback episode, we learn about how SRU took down a spree shooter at a gallery. An outside entity comes in to question the group one by one. She is focusing on Parker, as they have a shared past. Her partner was killed in a similar spree shooting and she never got over it. She has had it out for Parker ever since but it turns out that Parker was not at all to blame. In the mean time, the shooter at the gallery is targeting workers at a pharmaceutical company that gave her husband a bad drug which killed him and is seeking revenge for his death.