Erin Kelly

Republic Washington Bureau

Families who have lost loved ones in mass shootings said Tuesday they are renewing lobbying efforts aimed at Sen. Jeff Flake.

Victims%27 families said they want Congress to pass legislation to require background checks of would-be gun buyers who try to purchase firearms from private sellers on the Internet or at gun shows.

The group will travel to Phoenix on Friday to deliver postcards signed by constituents to Flake%27s office calling for %22common-sense laws to reduce gun violence.%22

WASHINGTON -- Families who have lost loved ones in mass shootings said Tuesday they are renewing lobbying efforts aimed at Sen. Jeff Flake, R-Ariz., and other members of Congress to convince them to support gun-control legislation.

"What could be more important than taking care of our kids?" said Richard Martinez, whose son, 20-year-old Christopher Michaels-Martinez, was shot to death on May 23 by a mentally ill gunman who killed six people near the University of California-Santa Barbara. "I will fight every day for the rest of my life to hold the people we send to Washington accountable because if it could happen to my family, it could happen to anyone's."

Martinez, who spoke at the National Press Club with other grieving parents, will travel to Phoenix on Friday to deliver postcards signed by constituents to Flake's office calling for "common-sense laws to reduce gun violence."

Victims' families said they want Congress to pass legislation to require background checks of would-be gun buyers who try to purchase firearms from private sellers on the Internet or at gun shows. Buyers already must undergo background checks to buy guns at retail stores.The families said that Martinez' cries of "not one more" shooting victim after the death of his son inspired them to redouble their efforts to seek congressional action.

Flake was one of 46 senators who voted on April 17, 2013, to oppose a bill by Sens. Joe Manchin, D-W.Va., and Patrick Toomey, R-Penn., to expand background check laws to include Internet and gun show sales.

Flake's spokeswoman said his position on the background check bill has not changed.

"He continues to hope that Congress takes up legislation to keep guns out of the hands of the mentally ill -- which would pass overwhelmingly -- instead of insisting on a universal background check bill, which doesn't have the votes to pass the Senate or the House," said Bronwyn Lance Chester, the senator's communications director.

The Manchin-Toomey bill was defeated when it failed to attract the 60 votes needed for passage. Sen. John McCain, R-Ariz., was one of four Republicans to support the bill, which was brought to a vote in the wake of the shooting at Sandy Hook Elementary School in Newtown, Conn. that killed 20 children and six adults in late 2012.

Opponents said the bill went too far in trying to regulate private sales of firearms between friends, neighbors and co-workers and would have put an undue burden on private individuals trying to sell their guns to people they know.

"I support background checks," Flake wrote in a Facebook post before his 2013 vote against the Manchin-Toomey bill. "In fact, I believe background checks need to be strengthened, particularly as they relate to those with mental illness. To this end I've co-sponsored S.480 with Senators Graham, Begich, and Pryor clarifying who should not be able to obtain a firearm due to mental illness. I believe our approach is preferable, and more workable, than the mental illness provisions in Manchin-Toomey."

In addition to delivering postcards to Flake's office, activists said they intend to deliver them to Republican Sens. Kelly Ayotte of New Hampshire, Saxby Chambliss and Johnny Isakson of Georgia, Dan Coats of Indiana, and Democratic Sens. Heidi Heitkamp of North Dakota and Mark Pryor of Arkansas.

The senators are being targeted because they voted against the Manchin-Toomey background check bill and because gun-control advocates believe they have a chance to change those lawmakers' minds, according to Erika Soto Lamb of Everytown for Gun Safety, a gun-control group that organized Tuesday's news conference.

However, other senators and House members also will be contacted, she said. More than 600,000 people have signed postcards calling for legislative action, and those postcards will be sent to senators, House members and governors throughout the country, Soto Lamb said.

Among those who attended Tuesday's news conference was Roxanna Green, mother of Christina-Taylor Green, the 9-year-old girl who was killed in the Tucson shooting rampage on Jan. 8, 2011. Six people died in the shooting and 13 others were wounded, including former Rep. Gabrielle Giffords, D-Tucson, who was hosting a meeting with constituents.

"When we laid her to rest, my heart broke," Green said of her daughter. "My heart is still broken. . . I have dedicated my life to keeping other parents from suffering this horrific pain."

Senate Majority Leader Harry Reid, D-Nev., has called on the Senate to revisit the background check issue in the wake of the shootings near UC Santa Barbara and the murder of two Las Vegas police officers and a civilian who were shot to death last week by a gun-toting husband and wife team.

But Reid has also acknowledged that he does not believe he has enough votes to pass a bill. Lawmakers from conservative states are especially wary of taking up gun-control bills in an election year.

"We all ask, when will this insanity of gun violence come to an end," said Tom Sullivan, whose son, Alex, was killed in the mass shooting at a movie theater in Aurora, Colo. in 2012 that left 12 people dead and 70 wounded. "What does it take for senators and congressmen to stand with us and have the courage to see something change?"