Sacramento, Calif. — Gov. Jerry Brown on Friday signed six gun control bills into law, including new restrictions on semiautomatic rifles and a requirement that ammunition purchasers undergo background checks, saying they will help “enhance public safety” in California.

The governor vetoed five other measures, including an expansion of the use of restraining orders to take guns from people deemed to be dangerous.

The governor’s action comes one day after the Legislature approved a dozen gun control bills that were introduced in response to the December mass shooting in San Bernardino that killed 14 people. The bills gained legislative momentum after last month’s massacre in Orlando, Fla., that claimed 49 lives.

“My goal in signing these bills is to enhance public safety by tightening our existing laws in a responsible and focused manner, while protecting the rights of law-abiding gun owners,” Brown wrote in a signing message Friday.

The action appeared to be a subtle shift for Brown, whose complicated record on gun control has been marked by skepticism about whether many proposals increase public safety without infringing on the rights of law-abiding gun owners.

At a time when mass shootings are occurring with escalating frequency, it appears Brown’s pragmatic side and his Jesuit training has made him more open to efforts to control firearms, according to Jaime Regalado, a professor emeritus of political science at California State University, Los Angeles.

The National Rifle Association Institute for Legislative Action accused the governor of exploiting the terrorist attacks for political gain.

“Gov. Jerry Brown today signed a draconian gun control package that turns California’s law-abiding gun owners into second-class citizens,” said Amy Hunter, the California spokesperson for the group. “The governor and Legislature exploited a terrorist attack to push these measures through even though the state’s already restrictive laws did nothing to stop the attack in San Bernardino.”

The bills signed by Brown include a ban on the sale of semiautomatic rifles equipped with so-called “bullet buttons” that allow the removal and replacement of magazines.

In 2013, Brown, a gun owner who hunted as a younger man, vetoed several gun control bills including one that would have outlawed the sale of semiautomatic rifles with detachable magazines, including those with bullet button features.

“I don’t believe that this bill’s blanket ban on semiautomatic rifles would reduce criminal activity or enhance public safety enough to warrant this infringement on gun owners’ rights,” Brown said at the time.

Administration officials said Friday that the earlier version was so broad as to have expanded California’s definition of an assault weapon. The bill he signed Friday, they said, was more precisely focused on the issue of how the ammunition magazines are quickly changed out.

Brown’s office noted that Lt. Gov. Gavin Newsom has qualified a more expansive gun control measure for the November ballot.

“The governor took swift action today and voters will have a chance to go even further in November, if they choose, with the lieutenant governor’s initiative,” said Evan Westrup, a spokesman for Brown.

Newsom, who had criticized the Legislature’s proposals as falling short of his proposed initiative, cast the governor’s actions as a start of reform that his ballot measure would complete.

Brown also signed bills restricting the loaning of guns without background checks to close family members, and another increasing penalties for filing false reports of firearms being stolen.