Democrats in Virginia are trying to make the public case for greater gun restrictions ahead of a special legislative session next month spurred by the fatal shooting of 12 people at a city office.

U.S. Sen. Tim Kaine, Secretary of Public Safety and Homeland Security Brian Moran and Richmond Mayor Levar Stoney joined family members of gun violence victims and other advocates Monday at a Richmond church to stress what they said is the need for greater gun control.

Kaine discussed his experience with gun violence as a former mayor of Richmond and governor of Virginia. Kaine was chief executive of the state in 2007 when a student with a history of mental problems fatally shot 32 people at Virginia Tech. He called it the worst day of his life.

Lawmakers in Virginia and Congress both have opportunities to pass worthwhile gun laws, including mandating universal background checks on gun buyers, he said.

"Now is the time for us to convert an opportunity into meaningful action," Kaine said.

Gov. Ralph Northam announced a July 9 special session in response to a mass shooting in Virginia Beach on May 31. Employee DeWayne Craddock used two semi-automatic handguns, a silencer and extended ammunition magazines to kill 12 people in and around a municipal office. All but one of the victims were former colleagues Craddock had worked with for years. Craddock was killed in an intense gunbattle with police.

Monday's event was part of a broader effort by the Northam administration to build public support for a slate of gun-control legislation ahead of the special session. His proposals include a ban on silencers and high-capacity magazines, as well as a broadening of the ability of local governments to prohibit guns in city buildings.

The governor said he also wants mandatory, universal background checks before gun purchases; a limit of one handgun purchase per month; and a "red flag" law that would allow authorities to seize weapons from people deemed a threat to themselves or others.

Northam, a Democrat faced with a gun-friendly, Republican-controlled General Assembly in the middle of a legislative election year, has also advocated that every lawmaker go on record for or against his proposals during the special session rather than quietly killing the bills in subcommittee.

Mark Whitfield, whose 9-year-old daughter was killed last month after being shot at a community cookout in Richmond, called for a comprehensive approach to curbing gun violence, including combating drug use and alleviating concentrated poverty. He said society needs to do a better job of identifying angry individuals who are prone to using guns to hurt others.

"We've got to start walking around checking people's temperatures," Whitfield said.

Republicans declined to comment on Monday's event, but have indicated they have no intention of following Northam's agenda. House Speaker Kirk Cox said Republicans will propose tougher penalties for those who use guns to commit crimes, including new mandatory minimum penalties. The governor has recently announced he will no longer sign any legislation that adds a new mandatory minimum requirement to state law.

Stoney, Richmond's mayor and a potential future gubernatorial candidate, said the public is tired of "spineless leadership" and wants immediate change. He also said minority communities are disproportionately suffering from gun violence.

"In cities like ours, black and brown people are dying each and every day," Stoney said. "So the question I have for the General Assembly is, how many more is it going to take?"