FBI Special Agent Richard Kolko said the agency was making the move at the request of the State Department to examine evidence in the Sept. 16 shooting and to pursue possible criminal charges in light of allegations that guards working for Blackwater might have shot innocent Iraqi citizens.
The FBI's involvement in the Blackwater investigation raises the possibility the private security contractor and its employees could face criminal charges, reports CBS News correspondent Bob Orr.
"The results of the investigation will be reviewed for possible criminal liability and referred to the appropriate legal authority," Kolko said.
Meanwhile, the head of Blackwater, Erik Prince, will face questions about the shootings Tuesday at a hearing on Capitol Hill, adds Orr.
Private security contractor Blackwater USA has had to fire 122 people over the past three years for problems ranging from misusing weapons, alcohol and drug violations, inappropriate conduct, and violent behavior, according to a report released Monday by a congressional committee.
The report, prepared by the majority staff of the House Oversight and Government Reform Committee, also says Blackwater has been involved in 195 shooting incidents since 2005, or roughly 1.4 per week.
In more than 80 percent of the incidents, called "escalation of force," Blackwater's guards fired the first shots even though the company's contract with the State Department calls for it to use defensive force only, it said.
"In the vast majority of instances in which Blackwater fired shots, Blackwater is firing from a moving vehicle and does not remain at the scene to determine if the shots resulted in casualties," according to the report.
The staff report paints Blackwater as a company that's made huge sums of money despite its questionable performance in Iraq, where Blackwater guards provide protective services for U.S. diplomatic personnel.
Blackwater has earned more than $1 billion from federal contracts since 2001, when it had less than $1 million in government work. Overall, the State Department paid Blackwater more than $832 million between 2004 and 2006 for security work, according to the report.
Blackwater, founded in 1997 and headquartered in Moyock, N.C., is the biggest of the State Department's three private security contractors. The others are Dyncorp and Triple Canopy, both based in Washington's northern Virginia suburbs.
According to the 15-page report, Blackwater has had more shooting incidents than the other two companies combined.
Blackwater spokeswoman Anne Tyrrell had no comment on the specifics in the report.
"We look forward to setting the record straight on this issue and others tomorrow when Erik Prince testifies before the committee," she said.
On Friday seven of the oversight committee's 18 Republican members called on Rep. Henry Waxman, D-Calif., the panel's chairman, to postpone the hearing until more is known about a recent incident in Iraq involving Blackwater guards.
On Sept. 16, 2007, 11 Iraqis were killed in a shoot-out involving Blackwater guards protecting a U.S. diplomatic convoy in Baghdad. Blackwater says its guards acted in self-defense after the convoy came under attack. Iraqi witnesses have said the shooting was unprovoked.
Several investigations are under way, including one by the State Department and another by a U.S.-Iraqi commission that is also examining the broader issue of how private security contractors in Iraq operate.
In a Sept. 28 letter, Rep. Dan Burton, R-Ind., and six other Republicans said the committee should wait until these investigations are complete.
"We feel it would be irresponsible for the committee to rush to judgment until all the facts are considered," the letter states.
Rep. Tom Davis or Virginia, the committee's top Republican, did not sign the letter.
Spokesman Brian McNicoll said Davis has no objection to the hearing taking place because several State Department representatives are scheduled to testify.
In addition to Prince, the witnesses include: David Satterfield, the department's Iraq coordinator, Richard Griffin, assistant secretary for diplomatic security, and William H. Moser, deputy assistant secretary for logistics management.