WASHINGTON (AP) -- The military-style rifles used in the deadly California shootings were legally purchased, the U.S. government said Thursday.
The two rifles were not specifically listed among the models outlawed under California's famously tough gun laws, and as long as each included a minor design change affecting how bullets are loaded into the weapon they would have been legal.
California limited access to high-powered, military-style rifles in 1989 and lawmakers passed further restrictions in 2000, when they banned specific types of AR-15 and AK-47 style rifles. Included in the ban were rifles that can use detachable ammunition magazines that hold more than 10 rounds and have other characteristics. Ammunition magazines that hold more than 10 bullets are also outlawed.
But rifles that aren't specifically listed in the ban are considered legal, as long as a tool is required to release the ammunition magazine. The change is intended to effectively limit the number of rounds the gun can fire because it presumably takes extra time to reload.
California's law prompted the gun industry to start marketing military-style rifles with so-called bullet buttons, a sort of sleeve that blocks quick access to the release button. Users can use the tip of a spare bullet or a tool to release the gun's magazine, although a small magnet can be attached to the button so that users can quickly press it using just their finger.
The executive director of the Violence Policy Center in Washington, Josh Sugarmann, said the gun industry was "cynically exploiting an inadvertent limitation" of California's assault weapons ban.
Law enforcement officials recovered a Smith and Wesson M&P-15 and an A15 made by Defense Procurement Manufacturing Services Panther Arms and two handguns after Wednesday's mass shooting at a disability services center and a shootout with a married couple suspected of carrying out the attack. Both rifles are sold with bullet buttons.
The assistant director of the FBI's Los Angeles office, David Bowdich, said Thursday that Syed Rizwan Farook legally bought the handguns. He said the rifles were bought by someone else though he did not provide any other details. The Bureau of Alcohol, Tobacco, Firearms and Explosives said earlier that all four guns were legally purchased.
The senior vice president and general counsel for the National Sport Shooting Foundation, Larry Keane, said the bullet button requirement does little to inhibit would-be criminals and doesn't "impact anyone but law-abiding citizens." The requirement, he said, frustrates sport shooters who often fire hundreds of rounds in target practice.
Police also found 2,500 rounds of rifle ammunition in a home shared by Farook and his wife, Tashfeen Malik. An additional 1,400 rifle rounds were found inside a car the pair used to evade police Wednesday, hours after the deadly shooting in San Bernardino. Police also recovered more than 2,000 handgun bullets. All told, the pair was equipped with roughly $2,000 worth of ammunition.
There are no legal limits on the volume of ammunition someone can buy. Keane said it is not uncommon for target shooters to buy larger volumes of ammunition at a time since they can routinely shoot hundreds of rounds during a weekend.
Follow Alicia A. Caldwell on Twitter at www.twitter.com/acaldwellap