We open on a man in a confessional chewing gum. He tells the priest that his wife caught him cheating, on his way out he flirts with a girl on the steps. As he approaches his car, a rifle shot kills him. Juliet interviews the man's spouse. She tells Juliet that she wished him dead, but didn't kill him. Sarah and Radner get ballistics from Jordan Sparks that the kill shot came from an AR-15 from 200 Yards away.
We see a man named Bird in the tub flashing back to Northern Iraq five years earlier when he worked with Kane. He insults his commander which causes a fight among the other men in front of Kane. A mortar hits the building causing wounds. In present day, he is getting increasingly agitated by the barking dogs and grabs his rifle and threatens to shoot them, but does not.
Kane takes a radio call about a man carrying a rifle, they respond to Bird's house, but he is no longer there. Bird just returned from his second tour, probably suffering from PTSD. Kane finds Bird at the VA and talks to him about the incident. Sarah and Radner are working late, when he attempts to hit on her. They get a call from Kane that there has been another sniper attack. They find a woman dead in front of the church. The local paper dubs the killer, "The Church Killer". We see a woman walking home who sees Bird watching her and confronts him. She had a past relationship with Bird and now lives with a banker. She tells Bird to stay away from her.
Back at the VA, Sarah and Radner interrogate a discharged sniper, but disqualify him after seeing his artificial limb. Kane talks to DA Clayton about Juliet being spotted at the scene of Kenneth's murder. Bird gets agitated again hearing the video game being played, until he finally pulls the plug and then tosses the table. Juliet questions Sarah about if she is seeing someone. Sarah then brings up Kenneth Rayner and questions Juliet about a possible rape. Juliet confesses that a past boyfriend forced himself on her. Kane confronts Bird about his alibi for the time of the shooting. Radner and Mason visit Bobby in jail about him making a deal.
Bird is at the station talking to Kane, and swears that he isn't the sniper, but feels like he could almost be him in his current state of mind. Radner flashes back to when he was doing drugs undercover, Juliet flashes back to her visit to Kenneth and bird flashes back to the war with this rifle in his hands as the killer kills two more in front of the church. Radner confronts Juliet about what he heard through the grapevine about what Juliet did to Kenneth. She admits that she beat Kenneth, but didn't kill him. Kane is talking to Sheriff Graves about new suspect who had a religious conversion and recently arrived from Pakistan. In the bull-pen, Graves asks Bird where he should place his police shooters. Bird chooses the next target based on the sniper's pattern.
A cop investigates an unattended van when he is surprised by the Sniper. Graves sees the Sniper while he is on a cigarette break dragging the officer. The sniper makes a run in a stolen police vehicle. Kane and Bird chase the Sniper after he abandons the car. Bird draws the Sniper's fire so Kane can flank him. Bird gets hit but insists on moving so the Sniper keeps his focus on him so Kane can get to the Sniper. As Bird lays there wounded twice, he flashes back to Iraq when the dogs attacked a wounded soldier and he had to fire on the dogs, repeatedly. Kane is able to catch up with the Sniper and take him down.
At the prison, Kane meets with Bobby and his lawyer. Bobby agrees to a plea deal that his partner shot and killed Kenneth after Juliet beat him up. Back at the VA, Bird jokes about returning to Iraq, but in reality decides he'll try for a job at the VA helping other vets.