Mall Shooter Jacob Roberts' Assault Rifle Jammed, Averting 'Much Worse' Tragedy, Sheriff Says

A man who killed two and injured one on Tuesday in a Portland, Ore., mall packed with holiday shoppers might have taken many more lives, authorities said, had his military-style assault rifle not jammed in the midst of his shooting spree.

Jacob Tyler Roberts, 22, was armed with an AR-15 semi-automatic rifle, which he stole from an acquaintance, Clackamas County Sheriff Craig Roberts (no relation) said at a press conference Wednesday.

The sheriff said the gun jammed as Roberts sprayed bullets into the Clackamas Town Center's food court, allowing potential victims to escape. Police estimated 10,000 shoppers were in the mall at the time of the shooting.

Roberts wore a hockey mask and a military vest holding multiple ammunition magazines, the sheriff said.

"I think we all need to be very thankful that this incident wasn't much worse," he said. "Based on the evidence we obtained, it appeared that the suspect's rifle did jam while he was attacking individuals in the food court."

Roberts was able to get the gun working again, the sheriff said, and fatally shot himself after fleeing to another area of the mall.

The AR-15 is the same type of semi-automatic assault rifle used in the Aurora, Colo., movie theater rampage this summer by James Holmes, a mentally unbalanced graduate student, accused of killing 17 and injuring more than 70.

A federal ban on manufacturing and importing the AR-15 and similar military-style rifles was passed in 1994 by the Clinton administration, but was allowed to expire in 2004. The law restricted the sale of magazines holding more than 10 rounds.

Gun control advocates said it was unsurprising that Roberts used the AR-15 during his spree. The semi-automatic rifle is modeled on the automatic M-16, until recently the primary U.S. infantry weapon. It features a pistol grip and fires a large, fast and especially deadly round.

"It was designed for war," said Josh Horowitz, executive director of the Coalition to Stop Gun Violence. "It's not a coincidence that people on shooting sprees don't go into malls carrying a long, cumbersome hunting rifle."

The 1994 assault weapon ban greatly reduced the availability of guns like the AR-15, but since the law expired, the market has boomed, Horowitz said.

"They're pouring off the assembly line," he said.

A spokesman for the National Rifle Association did not respond to a request for comment.

During this year's campaign, President Barack Obama spoke little about gun control, but did say he believed the assault weapons ban needed to be re-introduced. While governor of Massachusetts, former GOP presidential nominee Mitt Romney signed a bill banning assault weapons, but during his presidential campaign, Romney said no additional federal gun-control legislation was necessary.

Gun rights groups have fought tenaciously against attempts to reintroduce the assault weapons ban, saying the guns vary little from ordinary hunting rifles.

A number of recent polls suggest a majority of Americans support limited gun control legislation, such as an assault weapons ban, or a prohibition on high-capacity magazines, such as those used in the Aurora theater shooting.

"It's time to put the genie back in the bottle," Horowitz said. "The country is ready for this."