Law & Order: Organized Crime Season 3 Episode 1 revolves around a murder that Cosgrove witnesses. While out to lunch with his 15-year-old daughter, Cosgrove sees a girl her age get run over. While he is tending to her, she is shot and killed.

Cosgrove is determined to get to the bottom of this. The autopsy shows the girl was sexually assaulted. Cosgrove calls Benson, who tells him SVU has security cameras around a marina where a yacht involved in trafficking young girls is docked. A suspect is quickly identified and Cosgrove confronts him. The suspect, Serenko, gives him nothing, but Stabler shows up the next day and is angry because he's been investigating this guy and Cosgrove may have ruined his investigation.

Stabler and Cosgrove argue over jurisdiction. Cosgrove wants this case because a 15-year-old girl died. Stabler doesn't want to endanger his CI. Bell tells Stabler it's his call, but a girl is dead.

Stabler briefs Cosgrove, Shaw, and Dixon. Then he goes to meet his CI and sends him on a dangerous mission to clone the suspect's phone.

To find out what happens, watch Law & Order: Organized Crime Season 3 Episode 1 online.