You can find the episode on Apple TV and read more details on the Rizzoli and Isles Wiki . "Rizzoli & Isles" In Plain View (TV Episode 2015) - IMDb
In the Rizzoli & Isles Season 5, Episode 16 episode " In Plain View ," the team investigates the murder of Todd Reynolds, who was found dead on the side of the road. The case centers on a visiting detective, Mike Guthrie, who is revealed to be the killer acting on a long-held grudge from summer camp. Alongside the main investigation, Maura Isles tackles her own identity theft with the help of Angela Rizzoli, resulting in the imposter's arrest. [S5E16] In Plain View