The mystery surrounds two acquaintances, a man and a woman, whom I believe worked together. The man goes to the woman's apt to fix a TV (?), but for some reason, ends up killing her and setting her place on fire. I don't know how much of the mystery is resolved in the TV show, but the later TV movie involves another woman who is haunted by the ghost of the murder victim, and she helps solve the case so that the victim can find peace and justice.

Voice from the Grave (http://www.imdb.com/title/tt0115975/)