Son, 25, Arrested in Killing of Couple : Crime: Bodies were found buried in basement of Glassell Park home. The suspect had been treated for mental illness.

A former Army private, who authorities said was treated for mental illness after his discharge from the service, was arrested Monday on suspicion of killing his parents and burying them in a shallow grave in the basement of their Glassell Park home.

Stephen P. Durand, 25, was taken into custody at the Veterans Affairs Medical Center in West Los Angeles, where his brother took him after discovering signs that their parents had been shot in the living room of their home a few miles northeast of downtown Los Angeles.

Durand, who police said confessed that he had killed his parents after an argument Sunday, was being held without bail at Parker Center, Lt. Dave Waterman said.

Coroner’s investigators found the bodies of Robert Joseph Durand, 58, and Loris Theresa Durand, 54, in a grave three to four feet deep, dug in the dirt floor of their cellar, police said. Detectives said both had been killed with multiple shotgun blasts Sunday afternoon, then dragged outside and down several steps to the basement.

A collection of rifles, which belonged to the parents, was found on a table in the living room and two shovels and a pick were found in the basement, said Detective John Munguia. A bloodstained blanket, which police believe might have been used to drag at least one of the bodies downstairs, also was recovered.

“Oh, Stevie, Stevie,” said Julianna Marquez, 30, a neighbor who had grown up with Durand and his four older siblings on the quiet hillside around the 1700 block of Kilbourn Street. “I can’t believe he would do something like this.”

Police said they were told by family members that Durand had been treated for manic-depressive symptoms--characterized by wild mood swings--as an outpatient at the V.A. hospital. Hospital officials said Durand was first treated at the medical center in July, 1989, and last seen in December, but could not disclose the nature of his illness. They said the hospital could have done little to prevent the incident.

“You can’t hold somebody involuntarily unless you have some solid evidence that they’re a threat to themselves or others,” said Kathrene Hansen, a hospital spokeswoman. “Obviously, that determination had not been made.”

Durand, a graduate of Franklin High School who played trumpet in the marching band and enjoyed working on cars, joined the Army in 1985 and was awarded a sharpshooter badge for the M-16 rifle while in basic training, military officials said.

But his illness apparently began surfacing after a year’s duty in Germany, leading to his placement in 1987 on the temporary disability retired list, an Army spokesman said. On Dec. 1, 1988, with a rank of private first-class, he was given a medical retirement.

Longtime neighbors recalled that Durand had been found to be a manic-depressive after his discharge and resisted taking antidepressant medication. He often told friends that he did not need the medicine, and once complained that it was making him bald.

“As soon as he stopped the medication, he would go down,” said Joan Terpening, 56, who has lived across the street from the Durand home since 1968. “He would get depressed and didn’t think there was anything worth living for.”

Police could not confirm whether Durand was taking medication or had a prescription at the time of the killings. A prescription in Durand’s name was renewed last month, hospital officials said.

Neighbors thought that Durand had been off his medication for at least the last week, during which time they said he had been mugged in Eagle Rock and later turned up in Bakersfield, without money or ID. His mother, a secretary in the Los Angeles Unified School District’s division of adult and occupational education, took him Friday to the V.A. hospital, neighbors said. But he apparently slipped out without being treated.

“If anything, they were always afraid of him hurting himself,” said Terpening’s daughter Cheryl, 28.

Durand’s mother called police Saturday, asking that officers keep an eye out for him. But after going to church Sunday morning, she and her husband were not seen again. Durand’s brother, Robert Jr., became concerned when he called the house later that day and Stephen Durand told him that their parents had gone to Las Vegas, police said.

Officers said Durand told them that he had argued with his parents that day but would not disclose the nature of the dispute.

“All of a sudden, right next to my window, we got two killings,” said Joe Montano, as he looked over his fence at the Durands’ back yard, where the family patriarch, a semi-retired schoolteacher, often spent hours tending his avocado and orange trees. “It’s a sad thing.”