"Inside Edition" is saying that Pastorelli, who played the eccetric housepainter on the Candice Bergen comedy, was being investigated in the shooting death of 25-year-old girlfriend Charemon Jonovich.
Officials were getting ready to call the death a murder — rather than an accident or apparent suicide.
In 1999, Pastorelli, told police that he and Jonovich had been arguing and that she pointed the gun at herself not knowing it was loaded. It went off.
The shooting was initially classified as "undetermined."
But a law-enforcement source tells "IE" that the actor was aware he had become a suspect.
"We were planning to arrest him by the beginning of summer," the source says.
A syringe, a spoon and a plastic bag with white powder were discovered near his body.
Both Pastorelli, who was 49 when he died, and his girlfriend died in the same Hollywood Hills house.
The L.A. coroner officially changed the manner of Jonovich's death to "homicide" some time ago, citing two reasons: "staging of the crime scene, and scientific evidence the firearm was handled after the discharge," the show says.