SACRAMENTO, Calif. -- The deadly shooting in San Bernardino happened in a state with some of the toughest gun laws in the United States: California bars assault weapons, blocks the sale of large-capacity magazines and requires universal background checks for all gun purchases.
Authorities say they believe suspected gunman Syed Rizwan Farook and wife Tashfeen Malik had legally obtained two handguns and that two rifles were also legally purchased in California. Federal officials say the attackers had large-capacity magazines that violate California law in their SUV.
Since the attack Wednesday at a social service centre in Southern California, the state's strict laws and the apparent legal purchase of the weapons have set off a debate over the effectiveness of gun measures and whether getting tougher would help prevent more violence.
"Strong gun laws do prevent gun deaths. Not every law can prevent every gun death," said Allison Anderman, a staff attorney with the Law Center to Prevent Gun Violence in San Francisco. "They work most of the time."
The gun-control advocacy group rates California's gun laws No. 1 in the nation; the state ranks 42nd in its rate of gun deaths. Louisiana's gun laws were ranked 50th and it is No. 2 in deaths, according to the group's 2014 rankings.
Gun laws vary dramatically state-to-state, even city-to-city. The patchwork of regulations means it's often easy for determined gunmen to acquire weapons by skirting laws in their home state, they say. Untraceable weapons can be built from scratch using parts bought online.
As a result, gun control advocates in the days since the shooting have called for more stringent laws in California and nationwide. At least two state lawmakers say they will propose measures to close what they consider loopholes in the state's gun laws.
Crime Prevention Research Center president John Lott, a critic of additional gun laws who is often cited by the gun lobby, argued that the shooting illustrates how expanded background checks supported by President Barack Obama do not stop mass public shootings.
He noted that California, Colorado and Oregon -- sites of the three most recent shootings -- already have such laws in place.
"We're being told that even though these laws didn't stop these attacks in these states, somehow they would work in the rest of the country," he said. "I know the claim is, 'we don't expect it to do everything but it will do some.' Maybe they could point to one case where these laws would make a difference."
The FBI said Farook legally bought the two handguns used in the attack -- purchases that would have required a background check. And there is no indication he or Malik had any criminal record or history of mental illness that would have triggered California's unique law allowing authorities to seize weapons from those who aren't allowed to own them.
Federal officials are investigating whether the military-style rifles used were part of an illegal straw purchase, possibly from a former neighbour of Farook, and then given to Farook or Malik.
California limited access to high-powered, military-style rifles in 1989 and lawmakers passed further restrictions in 2000, when the state banned specific types of AR-15 and AK-47 style rifles. It also bans the sale of ammunition magazines that hold more than 10 bullets.
Legislation that would have banned so-called bullet buttons, which allow shooters to rapidly exchange empty magazines for ones fully loaded with bullets, stalled in the state Legislature two years ago.
David Hemenway, director of the Harvard Injury Control Research Center, said it is foolish to draw policy conclusions based on the facts of one specific shooting when the U.S. has more than 30,000 gun deaths per year.
He questioned whether the assault-style rifles used in San Bernardino should be legal anywhere.
"Are those guns needed for self-defence? Are they needed for hunting? They can kill a lot of people, which they succeeded in doing," he said.
Even in California, advocates for stricter gun control say there are holes in the law. The impression that the state has strict gun laws is "based on fact, but in some cases it's inaccurate," said Lt. Gov. Gavin Newsom, a Democrat.
Newsom has proposed a ballot initiative that would require on-the-spot background checks when buying ammunition, ban the possession, not just the sale, of large-capacity magazines with 10 rounds or more and require police reports when guns are lost or stolen.
Those measures might not address the specific circumstances of what happened in San Bernardino, he acknowledged. But, he said, "that doesn't mean they're not appropriate proposals to address the next circumstance and the next moment."
Associated Press writer Ryan J. Foley in Iowa City, Iowa contributed to this report.
