Stray (S03E06)

Two undercover Detectives set up a gun buy and are killed in the process. The other two Detectives, who were following them, make the gruesome discovery of the dead cops. They're alongside the two young men who were selling the guns, which turned out to be plastic, brutally killed inside the Detective's car while stopped at a rest station. Goren (Vincent D'Onofrio) and Bishop (Samantha Buck) track down the victims who work in a Staten Island custom auto shop. There they had the tools to make the fake guns. But they need to find their accomplice as they suspect he was the one who killed his friends, and the cops. They hope that since the bills were marked, that will help them find the killer. (iTunes)