The New York lawmakers are introducing legislation next week to boost funding to the Bureau of Alcohol, Tobacco and Firearms to have the agency perform annual checks of gun stores and increase mandatory penalties for those convicted of illegal gun trafficking.
"The ATF sometimes can't get around to a gun store for seven or eight years," said McCarthy (D-Mineola). "Now they would be able to do it on a yearly basis."
New York City Mayor Michael Bloomberg, Police Commissioner Ray Kelly and the family of Carol Kestenbaum, a Bellmore college student slain in Arizona in 2007, are scheduled to appear at the news conference.
Gillibrand spokeswoman Bethany Lesser declined to comment Monday.
McCarthy said the event will be her first joint appearance with Gillibrand. McCarthy, a staunch gun-control advocate whose husband was killed in the 1993 Long Island Rail Road massacre, in January promised to oppose Gillibrand in a primary over her past position on guns.
"It's a détente," McCarthy said Monday. "She's my senator, and we'll work with people who are working to reduce gun violence."
McCarthy, however, said she does not plan to endorse Gillibrand today - and won't unless she faces a threat from a Republican opponent. "She's going to win the primary, so what's she need my endorsement for?" McCarthy asked.