The Murder of Mark Sloan is the twenty-sixth episode of the fourth season of Diagnosis Murder, and the eighty-fifth episode overall.
Guest Stars: Mary Kay Adams (Vanessa Sinclair), Carol Bruce (Constance Lockwood), Stan Cahill (Dr. Brian Haywood), Michael Harney (Kurt Vaughn), Michael Holden (Hospital Board Chairman), Christy Perry (Nurse Christy)
Co-Starring: Carlo Felix (Delivery Man #2), Jay A. Michaels (Sam Rosser), Jeannie Zalasko (Lisa Farrell)
When it appears that Mark has been killed by a car bomb, Steve vigorously pursues the killer.
When it appeared that the show was 'on the bubble' (i.e., to be possibly cancelled), they made this episode where Dr. Mark Sloan was murdered, but left the ending open in case the series did get renewed.