SWAT barges into Whitsett's apartment to find Meeks holding a gun to the suspect's head. A gun found at the scene is a match to the one that killed Eddie. More lab tests point to the possibility that Meeks is a dirty cop. This is something Peter refuses to believe, so he has a chat with his old partner. Of course, Megan wonders why he didn't come to her first.
Megan tells Captain Perkins that she's recommending mandatory drug testing for his entire department. She hopes to flush out any cop who may be using. She ticks off the entire department, as Detective Lopez and his partner bring the urine samples to the lab. In an act of defiance, everything is delivered in one container. Hey, at least they put a nice bow atop the bottle.
Tensions are high with this case, but Peter reluctantly follows orders to retrieve the murder weapon for analysis. Megan gets a nasty cut on her hand as she does a test firing of the weapon. It's called a berretta bite. It can happen when discharging an unfamiliar firearm. Curtis finds a piece of latex in the box used to transport the gun. Peter convinces Meeks to comply with a DNA test. Afterwards, he's arrested for the murder of his partner.