WASHINGTON (AP) -- A federal law enforcement official says the semi-automatic assault rifle used in the deadly Colorado movie theater shooting jammed during the attack.
The official said late Saturday the rifle had a high-capacity ammunition magazine and that it jammed, forcing the suspect James Holmes to switch to another weapon. The official spoke on condition of anonymity to discuss the investigation.
Aurora Police Chief Dan Oates has said a 100-round drum magazine was recovered at the scene of the shooting in suburban Denver. Oates said such a weapon would be able to fire 50 to 60 rounds a minute.
Police say Holmes also had two Glock pistols and a shotgun.
Holmes, a 24-year-old former graduate student, is in custody. The attack early Friday killed 12 people and wounded nearly 60 others injured.

AURORA, Colo. (AP) -- Navy officials say one of the people killed in a Colorado movie theater shooting was a Navy veteran.
Navy spokesman Lt. Cmdr. Chris Servello says 26-year-old Jonathan T. Blunk of Aurora, Colo., served three tours of duty between 2004 and 2009.
Military officials have also identified two active service members, 27-year-old Navy sailor John Larimer of Crystal Lake, Ill. and 29-year-old Air Force Reservist Jesse Childress Thornton, Colo., as two the 12 victims.
Larimer was a Navy cryptologist at nearby Buckley Air Force Base. Navy Cmdr. Jeffrey Jakuboski says four other sailors were at the theater, including one who was injured and treated at the scene.
Air Force officials say Childress was a cyber-systems operator based at Buckley. Another Air Force airman from the base was wounded during the shooting.

AURORA, Colo. (AP) -- Aurora, Colo., Police Chief Dan Oates says James Holmes planned the rampage that killed 12 people and injured dozens more at a suburban movie theater with "calculation and deliberation." He says Holmes received multiple deliveries by mail for four months to his home and school and bought thousands rounds of ammunition on the Internet. Oates says authorities believe that's how he armed himself for battle and was able to rig his apartment with explosives aimed at killing first responders.
Authorities say all hazards have been removed from the suspect's suburban Denver apartment and residents in surrounding buildings can return home.
The exception is Holmes' apartment building, where authorities are still collecting evidence. Inside the apartment, the windows have been covered with black plastic to prevent onlookers from seeing in. Before authorities covered the windows, a man in an ATF T-shirt could be seen measuring a poster on a closet that advertised a DVD called "Soldiers of Misfortune." The poster showed several figures in various positions playing paintball, some wearing masks.

DENVER (AP) -- The University of Colorado says shooting suspect James Holmes had a federal grant to study neuroscience.
University spokeswoman Jacque Montgomery said Saturday that Holmes was one of six neuroscience students at the school to get National Institutes of Health grant money. She didn't know how much money he got.
The NIH says the university decides who gets the grants. Criteria for receiving the grant weren't immediately clear.
The university says Holmes enrolled in the program last year and was withdrawing. Montgomery says Holmes didn't indicate why he was withdrawing.
Montgomery says Holmes took an oral exam at the end of the semester that all students must pass to continue in the program. She says privacy laws prevent the school from releasing his score.