Sen. Barbara BoxerBarbara Levy BoxerOnly four Dem senators have endorsed 2020 candidates Hispanic civil rights icon endorses Harris for president California AG Becerra included in Bloomberg 50 list MORE (D-Calif.) pointed to gun laws in her home state as evidence that commonsense reforms can prevent mass shootings.

“The fact is, sensible gun laws work, we’ve proven it in California, and we’re not going to give up,” the senator said in a press conference on Thursday.

Boxer’s comments come a day after the mass shooting in San Bernardino, Calif., in which 14 people were killed and 21 injured.

Boxer said California has passed several gun regulations since the 1990s, which she said have contributed to a statewide decline in gun violence.

"In California, since the 1990s, we have passed a number of important gun safety laws," she said. "And over that period of time, we have had a reduction in gun violence of 56 percent."

"Now clearly what we see is, this is not enough. That is why we need national laws," she added.

Earlier in the day, Boxer took to the Senate floor to urge her colleagues to pass bans on “military-style” weapons.

“The scene looked like a war zone, and there’s a reason for that,” she said. “Again, because these weapons, they’re designed for the military, they’re designed for the police. And I have to be honest with you, sir, I have never heard one persuasive argument about why anyone else would need to have this type of weapon.”

“These weapons of war, they just don’t belong on our streets or in our communities,” she added.

Boxer said Congress must “take action now, before something like this happens again.”

-Updated at 6:02 p.m.