LOS ANGELES, Mar. 18 — After using Charles Manson to launch a career in film making, a San Fernando Valley man is again seeking the infamous murderer’s help — this time as a witness in a lawsuit against talk show host Geraldo Rivera.

Robert Hendrickson, 45, of Woodland Hills, is scheduled to ask a Los Angeles Federal Court judge Monday for permission to subpoena Manson at a state prison in Corcoran, Calif, where Manson is serving a life sentence for his conviction in the 1969 cult murders of seven people, including actress Sharon Tate.

In papers filed with the court last week. Hendrickson says Manson is one of the only available witnesses who can testify about the making of “Manson,” a 1972 documentary film at the center of his copyright battle with Rivera and Rivera’s production company, the New York-based Investigative News Group.

“Most of them are in jail or dead. Even my co-producer was murdered,” Hendrickson said in an interview. “Charlie (Manson) and (Manson follower) Lynette Fromme are just about the only ones left.”

Hendrickson filed the federal suit against Rivera last May, claiming that Rivera used excerpts from “Manson” in a televised special called “Murder — Live from Death Row” that aired in April 1988.

Lawyers for Rivera claim the Investigative News Group paid a video distributor $3,000 to use the excerpts, but Hendrickson says the deal was made without his permission.

The case is set for trial April 10.

Hendrickson said he never had problems with his copyright on the film until the recent spate of “tabloid” television shows that focused on the Manson case and other sensational crimes. Rare footage of the early days of the Manson cult are now in great demand by television producers, he said.

“It would be extremely unusual to permit live testimony by a prisoner,” said Vincent Cox, one of the lawyers for Rivera. “Just think of the havoc that would be created, if all you had to do was subpoena someone like that, to get them out of jail.”

A key issue at the hearing will be Hendrickson’s request to expand the usual 100-mile limit within which witnesses legally can be subpoenaed. The state prison in Corcoran is about 190 miles from Los Angeles.

Defense lawyers claim that Hendrickson should have had Manson give a recorded deposition in the case, which could have been taped in his prison cell. But because Hendrickson missed the Jan. 31 deadline for submitting documented evidence for the trial, the only option he has is to subpoena Manson to appear in person, Cox said.

Hendrickson said he met Manson and other members of his “family” in 1969, when a few of Manson’s cult followers appeared as extras in a movie he was producing.

After the Tate-LaBianca murders and Manson’s arrest, Hendrickson said, he continued his relationship with the family, filming the members’ activities before and during the Manson trial.

By JOHN POLICH