The Rockford Files: Friends and Foul Play (1996) DVD

Rockford's friend from the Sandcastle, Babs, is investigating the murder, 18 monthes earlier. She suspects a local mobster and is harassing him to get him to make a mistake that she can tell the police about. Unfortunately the mistake he makes is killing her when Jim Rockford is on the job. As usual a group of friends collects to help solve the crime, and Jim signs up for Lt. Chapman's class on criminology to get the inside track on the investigation, and becomes the class cut-up.