MADISON, Wis. (AP) — A Wisconsin judge will decide whether to file charges against a police officer who killed a man sitting in a parked car using a rarely invoked legal process. Joseph Mensah shot three people in a span of five years while he was an officer in the Milwaukee suburb of Wauwatosa. Prosecutors declined to charge him each time. The family of one of the men killed, Jay Anderson, asked a Milwaukee judge in February to launch a John Doe investigation into Anderson’s death. It’s similar to a grand jury proceeding in which a judge hears witness testimony and decides whether to file charges directly, bypassing prosecutors. The judge is set to make his decision Friday.