Updated

Two California soldiers shot to death in Iraq were murdered by Iraqi civil-defense officers patrolling with them, military investigators have found.

The deaths of Army Spc. Patrick R. McCaffrey Sr. and 1st Lt. Andre D. Tyson were originally attributed to an ambush during a patrol near Balad, Iraq, on June 22, 2004.

But the Army's Criminal Investigation Command found that one or more of the Iraqis attached to the American soldiers on patrol fired at them, a military official said Tuesday.

A Pentagon spokesman knew of no other similar incident, calling it "extremely rare."

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The Army has conducted an extensive investigation into the deaths but declined to provide details out of respect for relatives of the soldiers, spokesman Paul Boyce said Tuesday evening.

It was unclear whether the investigators had established a motive or arrested any suspects.

The families of McCaffrey and Tyson were to be briefed on the report's conclusions Tuesday and Wednesday by Brig. Gen. Oscar Hilman, the soldiers' commander at the time, and three other officers.

"When they come I have my list of questions ready, and I want these answers and I don't want lies," McCaffrey's mother, Nadia McCaffrey, said in a telephone interview with The Associated Press.

Soldiers who witnessed the attack have told her that two Iraqi patrolmen opened fire on her son's unit. The witnesses also said a third gunman simultaneously drove up to the American unit in a van, climbed onto the vehicle and fired at the Americans, she said.

"Nothing is clear. Nothing is clear," she said. Her son was shot eight times by bullets of various calibers, some of which penetrated his body armor, she said. She believes he bled to death.

Nadia McCaffrey has become a vocal critic of the war in Iraq, and said her son had reservations about it, too, though he served well and was promoted posthumously to sergeant.

"I really want this story to come out; I want people to know what happened to my son," she said. "There is no doubt to me that this (ambushes by attached Iraqi units) is still happening to soldiers today, but our chain of command is awfully reckless; they don't seem to give a damn about what's happening to soldiers."

Iraqi forces who had trained with the Americans had fired at them twice before the incident that killed Patrick McCaffrey, and he had reported it to his superiors, she said.

Boyce said the U.S. military remained confident in its operations with Iraqis.

"We continue to have confidence in our operations with Iraqi soldiers and have witnessed the evolution of a stronger fighting army for the Iraqi people," he said.

"The Army is committed to investigating each battlefield death and providing accurate information to families."

Patrick McCaffrey joined the National Guard the day after the terrorist attacks of Sept. 11, 2001, his mother said.

Tyson's family could not be located, and a message left with his former unit was not immediately returned.

McCaffrey, 34, and Tyson, 33, were members of the California National Guard. Both were assigned to the Army National Guard's 579th Engineer Battalion, based in Petaluma.

Sen. Barbara Boxer, D-Calif., pressed the Pentagon for answers about the case when Nadia McCaffrey was unsatisfied by explanations from the military.

"Mrs. McCaffrey is set to receive a briefing from Pentagon officials (Wednesday) afternoon in California, during which we hope they will provide her with a full report of the facts surrounding Sgt. McCaffrey's death," said Natalie Ravitz, a Boxer spokeswoman.