(CNN) Virginia Gov. Ralph Northam called a special session of the state legislature to take up gun-control measures in the wake of Friday's mass shooting in Virginia Beach.

"I will summon the members of the Senate and the House of Delegates to meet in special session for the purpose of passing common sense public safety laws," Northam said at a press conference Tuesday.

He added, "I will be asking for votes and laws, not thoughts and prayers."

Twelve people were killed in an attack at a Virginia Beach city building after a gunman, who was a former employee, opened fire Friday afternoon. Law enforcement officers found two .45-caliber pistols legally purchased by the shooter at the scene — one pistol had a suppressor and several empty extended magazines, police said. The gunman was killed in a shootout with police. Questions remain about why the shooter purchased the weapons and how long he was planning his attack.

Northam said "this weekend's tragedy" must "instill in us a new level of urgency to act."

"If we can save one life because we acted now, it is worth it," he argued.

Back in January, Northam introduced a slate of gun control bills ahead of the start of the year's legislative session, including a universal background checks bill, a ban on assault firearms, and an "extreme risk protective order."

Northam said Tuesday he will propose many of the same ideas he pushed in January.

The other proposals Northam wants the legislature to consider are reinstating Virginia's one-handgun-a-month law, increasing penalties for leaving loaded, unsecured firearms around children and requiring people to report lost and stolen firearms.

But Virginia House of Delegates Speaker Kirk Cox said Republicans will plan to put forward legislation "to stiffen penalties for those who use firearms to commit crimes, including mandatory minimum sentences."

"While the Governor can call a special session, he cannot specify what the General Assembly chooses to consider or how we do our work," Cox said in a statement Tuesday. "We intend to use that time to take productive steps to address gun violence by holding criminals accountable with tougher sentences — including mandatory minimums."

Virginia's Lieutenant Gov. Justin Fairfax and Virginia Attorney General Mark Herring echoed Northam's calls for action from Virginia's state lawmakers during Tuesday's press conference.

"Every day we fail to act, we dishonor the memory of those lost and we give our blessing to a status quo that ought to horrify us," Herring said.

Virginia's House Minority Leader, Del. Eileen Filler-Corn, appealed to Republicans to work with Democrats and argued "when it comes to guns, doing nothing is not an option."

Some of the state's Democratic lawmakers applauded Northam's decision to call them back to Richmond.

"I thank the Governor for his leadership on this issue and I look forward to heading down to Richmond to pass legislation which addresses gun violence in the Commonwealth," Virginia Delegate Karrie Delaney said on Twitter.

Cox, however, called Northam's decision "hasty and suspect when considered against the backdrop of the last few months" — referring to a scandal Northam was caught up in earlier this year stemming from a racist photo on his 1984 medical school yearbook page. Northam has denied being in the photo.

He argued that the special session is more likely to "inflame political tensions than produce substantive public policy changes that will keep people safe."

Northam's office said the governor will announce the date of the special session in the coming days.

A spokeswoman for the National Rifle Association, Jennifer Baker, accused Northam of "exploiting a tragedy" with the move.

"Gov. Northam is following the gun control playbook by exploiting a tragedy to push his failed political agenda," Baker said in a statement. "The fact is none of the governor's gun control proposals would have prevented the horrible tragedy at Virginia Beach."

"If Gov. Northam is genuinely interested in pursuing policies that will save lives, he should focus on prosecuting violent criminals and fixing our broken mental health system, instead of blaming Virginia's law-abiding gun owners for the act of a deranged murderer," she said.

This story has been updated.