SANTA ANA, Calif. (AP) — A man representing himself in a potential death penalty trial involving five grisly 1970s murders sparred Monday with a retired homicide investigator after the witness explained graphic evidence from one of the slayings.

Rodney James Alcala, 66, faces five counts of first-degree murder in the strangling and beating deaths of four Los Angeles County women and one Orange County child from 1977 to 1979, when he was arrested in Seattle.

Alcala, a photographer with a reported IQ between 160 and 170, was twice sentenced to death for the murder of 12-year-old Robin Samsoe, but both convictions were overturned on procedural matters.

Prosecutors are retrying Alcala in that matter and added four Los Angeles County murders to the case in 2005 after DNA hits linked the cold cases to him. Alcala has pleaded not guilty and denied special circumstance allegations of murder in the commission of rape, torture and burglary.

The former UCLA undergraduate student deferred his opening statement until later in the trial, but objected multiple times Monday to testimony from a retired LAPD homicide detective.

Detective Kirk Mellecker told jurors that he could tell from bruises and bleeding patterns that many of the injuries suffered by 18-year-old victim Jill Barcomb occurred while she was still alive, including a “very vicious” bite to her breast and beatings to her face and head.

The retired detective also said Barcomb must have resisted because she was strangled with a belt, nylons and her pant legs and didn’t succumb immediately to a beating with a 7-inch-long rock. He showed the bloodstained rock to jurors.

Barcomb’s body was found Nov. 10, 1977, on a dirt road in a canyon in the Hollywood Hills.

“You’ve got to remember, she’s got three ligatures around her neck and her skull bashed in,” Mellecker said. “She’s a spunky kid. She doesn’t want to die. She’s fighting it.”

Alcala, who was dressed in a beige suit, turquoise dress shirt and glasses, objected to Mellecker’s testimony and engaged him for several minutes in a debate about his medical qualifications before Orange County Superior Court Judge Luis Briseno intervened.

“I cannot allow this kind of a dialogue or we’ll be here way past April,” the judge said.

Outside the presence of the jury, Briseno reminded Alcala to pose questions to witnesses and refrain from stating opinions until closing arguments.

Earlier, prosecutor Gina Satriano described all five slayings for jurors in her opening statement, from Barcomb to the 12-year-old Robin Samsoe, whose mutilated body was later found in the Angeles National Forest.

All the adult victims were raped and strangled — some so forcefully that the blood vessels in their eyes burst and bones in their throat and jaw broke, Satriano said.

Alcala was not arrested until July 24, 1979, about a month after Samsoe disappeared while on her way to a ballet lesson in Huntington Beach in Orange County.

Investigators were not able to determine Samsoe’s cause of death or if she had been sexually assaulted because of the condition of her body, which was found 12 days later.

Alcala’s former defense attorney, Richard Schwartzberg, has said the Samsoe case is based on weak circumstantial evidence, and that Alcala has an alibi for the day Samsoe disappeared.

Evidence will include testimony from four other then-teenagers who were approached by Alcala the day Samsoe was abducted, as well as a 30-year-old composite sketch of Alcala done from recollections by Samsoe’s friend and photographs taken by Alcala on the beach, Satriano said.

Samsoe’s friend last saw her as Samsoe pedaled home to collect her ballet slippers on her way to her lesson. Her mother had arranged for her to answer phones at the ballet studio in exchange for free lessons.

“Robin never made it to her ballet lesson. In fact, she never made it home,” Satriano said. Alcala was arrested about a month later in Seattle, where he had moved abruptly after TV stations began running the composite sketch. Investigators found a jewelry pouch in a storage locker in Seattle that contained Samsoe’s earring and another earring bearing the DNA of another alleged victim, 32-year-old Charlotte Lamb, authorities said.

Alcala’s first conviction in the Samsoe case was overturned after the state Supreme Court found that allowing evidence about Alcala’s previous record of rape and assault on young girls improperly prejudiced the jury.

His second conviction was overturned by the 9th U.S. Circuit Court of Appeals, which found that his attorneys hadn’t presented evidence of an alibi and hadn’t properly developed other evidence.

In 2008, the state Supreme Court upheld the prosecutors’ decision to combine the cases and try all five in Orange County.

Now, Samsoe’s family is bracing to hear the graphic evidence for a third time.

“The only thing we get out of it now is that at least there are four other families now who know (the killer) isn’t still out there, someone living next door to them or something,” said Robert Samsoe, who was 13 when his sister vanished.

“For us, there’s no closure, there won’t be no closure until he dies in jail,” he said.