Damage to the vehicles in the convoy has been held up by North Carolina-based Blackwater as proof that its security guards were defending themselves against an insurgent ambush when they fired into a busy intersection, leaving 17 Iraqi civilians dead.
U.S. military investigators initially found "no enemy activity involved" and the Iraqi government concluded the shootings were unprovoked.
The repairs essentially destroyed evidence that Justice Department investigators hoped to examine in a criminal case that has drawn worldwide attention. The Sept. 16 shooting has strained U.S. relations with the Iraqi government, which wants Blackwater expelled from the country. It also has become a flash point in the debate over whether contractors are immune from legal consequences for their actions in a war zone.
Blackwater's four armored vehicles were repaired or repainted within days of the shooting, and before FBI teams went to Baghdad to collect evidence, people close to the case said. The work included repairs to a damaged radiator that Blackwater says is central to its defense.
The damage and subsequent repairs were described to The Associated Press by five people familiar with the case who discussed it in separate interviews over the past month. All spoke on condition of anonymity because of the sensitivity of the case.
The repair work creates a hurdle for prosecutors as they consider building a case against any of the 19 guards in the Sept. 16 convoy. It also makes it harder for Blackwater to prove its innocence as it faces a grand jury investigation and multiple lawsuits over the shooting. The company is the target, too, of an unrelated investigation into whether its contractors smuggled weapons into Iraq.
Blackwater spokeswoman Anne Tyrrell said any repairs "would have been done at the government's direction." Blackwater's contract with the State Department requires that the company maintain its vehicles and keep them on the road.
The State Department would not comment on whether it ordered the repairs to the vehicles involved in the shooting.
Blackwater's chief executive, Erik Prince, has pointed to the damaged trucks to counter accusations that his contractors acted improperly.
In interviews this fall, he said three of Blackwater's armored vehicles were struck by gunfire and that the radiator from one was "shot out and disabled" during the shooting in Baghdad's Nisoor Square. An early two-page State Department report supports Prince's statements. The report noted the Blackwater command vehicle was "disabled during the attack" and had to be towed.
Prince has indicated he expects the FBI investigation to clear his company. Yet people close to the case say the vehicles and radiator alone probably will not be enough to do that because repairing the trucks made it difficult for investigators to say whether the convoy was fired on - or not.
As for the radiator, investigators have verified that it was damaged. But it, too, was repaired before the FBI arrived two weeks after the shooting.
No bullets were found inside the radiator to prove it had been shot, as opposed to being broken during routine use. That makes it hard for scientists to say for certain what caused the damage or when, according to those close to the case.
The preliminary State Department report noted "superficial damage" to the vehicles; and photographs exist showing bullet damage. People who have seen the photos said there are no time stamps or other indications of when and where that damage occurred.
One photo, obtained and broadcast by CBS News, bore no notations indicating when it was taken or even if the vehicle pictured was involved in the shooting.
The evidence gaps will force investigators to rely more heavily on testimony and other statements from witnesses. But even those efforts have been hampered by a State Department deal that gave Blackwater guards limited immunity for their statements following the incident. As a result, the Justice Department cannot use those interviews in its criminal investigation.
There were 19 security guards at the scene. Investigators believe only a few fired their weapons. Investigators are pushing ahead with the search for additional evidence and so far are focusing on as many four guards who could face criminal charges.
Over the past two months, prosecutors have brought several guards before a Washington grand jury to describe their recollection of the shooting. According to the initial State Department report, the shooting occurred as the Blackwater convoy was responding to a car bombing about a mile outside the U.S.-protected Green Zone, which houses the Iraqi government and several embassies.
James Sweeney, a lawyer representing several guards, would not discuss the forensic gaps or whether the grand jury investigation is helping authorities bridge them. He said Blackwater guards are patriots, not aggressors.
"They are good, solid intelligent Americans. They're good people," Sweeney said. "They're protecting U.S. diplomats."
Blackwater is the largest private security company protecting U.S. officials in Iraq. It has been paid more than $1 billion from federal contracts since 2001. Despite criticism, Blackwater notes that no official under its protection has been killed or seriously injured.
Blackwater also strongly denies wrongdoing in a weapons smuggling investigation by federal officials in North Carolina. Two former employees, who prosecutors say are aiding the investigation, were sentenced to probation Thursday on gunrunning charges.
Blackwater and other contractors operate in a legal gray area. They are immune from prosecution in Iraqi courts. If the Justice Department wants to bring criminal charges such as assault, manslaughter or murder in a U.S. court, prosecutors would have to do so under the Military Extraterritorial Jurisdiction Act.
That would require the government to show that State Department contractors were "supporting the mission of the Department of Defense overseas." Defense lawyers are expected to argue that guarding diplomats was a purely State Department function, one independent from the Pentagon.
The Justice Department has said it could be some time before it decides whether it will bring charges in the case.
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