A sniper in the park shoots and kills one man and shoots and wounds another. The only witness is a homeless man who is possibly mentally ill and believes that he is a werewolf. Maura attempts to get him to tell what he saw in the park. Turns out he tried to stop the sniper from shooting Jeremy Fritz and bit his hand which is why the shot didn't kill Jeremy.

Maura realizes that her witness may actually have a brain tumor so she brings him to the hospital for a CAT scan. The sniper goes to the hospital to try and kill the witness. Maura scares him off and chases him down with a scalpel. When he grabs her in the stairwell, she stabs him in the leg which slows him down so that Jane can capture him.

Maura finds out that the witnesses name is Michael and his family has been searching for him. His tumor is treatable. The sniper killed Jeremy because he fired him and only killed the other victim to cover his tracks.
Maura's boyfriend Jack moves to New Mexico to be near his daughter.

Watch Rizzoli & Isles Season 5 Episode 17 Online right here at TV Fanatic.