Question: brooklyn 99 why is jake in prison?
Answer: The season 4 finale of Fox's “Brooklyn Nine-Nine” left off with two of the squad's most integral characters, Detectives Jake Peralta (Andy Samberg) and Rosa Diaz (Stephanie Beatriz) incarcerated for a crime they didn't commit after trying to infiltrate a dirty squad headed by Lt. Melanie Hawkins (Gina Gershon).