“ Bosch: Start of Watch ” is starting to build out its main cast, with Ariana Guerra joining the series. The “Bosch” prequel, which was picked up to series at MGM+ in October 2025 , will star Cameron Monaghan as a young Harry Bosch in his rookie days in the LAPD, while Omari Hardwick will play veteran officer Eli Bridges. “Bosch: Start of Watch” will take place in 1991 Los Angeles. The official logline states, “The series will explore a city on the edge, teeming with racial tension, gang