Let’s face it: When it comes to solving mysteries, the five staff members of Pittsburgh’s Citizen Police Review Board earn about as much respect as Fred, Daphne, Velma, Shaggy and Scooby-Doo. Perhaps that’s because the mysteries they are dealing with are so difficult to unravel that they may as well be chasing ghosts. The review board was created to hold police accountable at a time when everyone -- from everyday citizens to the NAACP -- seemed to be filing complaints and even lawsuits over the behavior of Pittsburgh’s police department.