WASHINGTON — The Army spent nearly $500 million on no-bid contracts for private security guards who included people with criminal records, according to congressional investigators.

In a report released last week, the Government Accountability Office said the Army awarded sole-source contracts to two Alaska Native firms that placed security guards at 46 military installations in the U.S.

"The Army's procedure for screening prospective contract guards is inadequate and puts the Army at risk of having ineligible guards protecting installation gates," GAO said.

The report said 89 guards were hired at two bases even though they had criminal records, including assaults and other felonies.

The two firms given no-bid contracts were Chenega Integrated Systems and Alutiiq Security and Technology. They got the awards under a special Small Business Administration program. The two firms hired security subcontractors and provided guards to key Army installations including Fort Bragg in North Carolina, Fort Carson in Colorado, West Point in New York and Fort Knox in Kentucky.

In addition, GAO found that the Army does not adequately confirm that guards have been trained; that guards were certified by the contractor before training was finished; and that in one case a contractor falsified training records.

After the Sept. 11 terrorist attacks, active duty and reserve troops were sent to war in Iraq and Afghanistan, creating a need for military security guards at U.S. bases. Congress approved a waiver, effective through September 2007, allowing the use of private contractors to fill the guard positions.

The Army awarded $733 million for guards at 57 installations, but about $238 million was awarded in competitive bidding contracts at 11 Army bases.

Philip Grone, deputy undersecretary of defense for installations, said continued wartime requirements for active duty and reserve troops will make it necessary to use more security guard contractors. He said the Army is putting out new competitive bid requests for security contracts, and has changed procedures to better monitor the screening and training of the guards.