The official, who has direct knowledge of the investigation under way by the Naval Criminal Investigative Service, said evidence found thus far indicates Marines entered the town of Hamdaniya in search of an insurgent and, failing to find him, grabbed an unarmed man from his home and shot him.

The AK-47 and the shovel, which were taken from another home before the shooting, were meant to make it look like the man had been digging a hole for a roadside bomb and was killed in an exchange of gunfire, the official said.

The official spoke only on condition of anonymity because he was not authorized to discuss the matter publicly.

Seven Marines and a Navy corpsman are being investigated in this case, but no charges have been filed. All eight were removed from duty with the 3rd Battalion, 5th Marine Regiment in Iraq and are being held at Camp Pendleton, Calif.

Jeremiah Sullivan III, an attorney for the unidentified Navy corpsman who is among the eight accused, told a news conference in San Diego on Tuesday that he could not comment on news reports that the killing of the Iraqi was premeditated murder because he had not yet seen any investigation findings or heard any charges.

Sullivan said his client is being held in solitary confinement in the brig at Camp Pendleton and is allowed one brief exercise period per day, during which he remains shackled at the hands, waist and ankles. Anytime he walks in the recreational yard, he is escorted by at least one military prison guard who grasps onto his waist shackles at all times. Sullivan said this was "cruel and unusual."

"The reason they are in such oppressive conditions is because of the sensational nature of this case, and that's wrong," Sullivan said.

Camp Pendleton spokesman Lt. Lawton King said that "given the preliminary findings" of the investigation, it was decided that the servicemembers would be held in "the maximum level of restraint" and are escorted as a safety precaution. King said the prisoners are allowed to have visitors, reading materials, television, music and visits by a chaplain and are allowed to shop at the brig convenience store.

The Marine Corps and Pentagon spokesmen have refused to comment on any aspect of the Iraqi man's death since the investigation was announced May 24. In that announcement the Marines said Maj. Gen. Richard C. Zilmer, the commander of all Marine forces in Iraq, had asked for a criminal investigation after a preliminary probe found sufficient information to warrant further investigation.

This case is unrelated to the killings of 24 civilians last Nov. 19 in the city of Haditha by Marines from another unit. The NCIS also is investigating that case, and a parallel probe is reviewing what Pentagon officials have said appeared to be efforts by the Marines at Haditha to cover up the true circumstances of those killings.

The Washington Post reported on Monday that the Iraqi victim at Hamdaniya was Hashim Ibrahim Awad al-Zobaie, a 52-year-old disabled man shot four times in the face. His family told the Post that a small group of U.S. servicemen came to them last week and offered the family money in exchange for supporting the Marines' version of the killing.

© 2006 The Associated Press