Updated

A dozen survivors of the January shooting rampage in Tucson, Ariz., that severely wounded Rep. Gabrielle Giffords (D-Ariz.) lobbied federal lawmakers Tuesday to broaden federal background checks on potential gun owners.

The effort marked the first time since the shooting, which killed six and wounded 13, including Giffords, that a large group of Tucson survivors have banded together to weigh in on the politically charged issue.

"Tucson is yet another extreme tragic example of what is at stake each and every time a gun is placed into the wrong hands," said Patricia Maisch, who witnessed the shooting and wrested a magazine of ammunition from the accused shooter, Jared Loughner. Maisch urged lawmakers to "fix the broken system" of background checks.

The lobbying effort, which included private meetings with lawmakers and an appearance before a Senate subcommittee, was organized by a coalition of mayors pushing for tighter gun control. The mayors -- led by New York Mayor Michael Bloomberg and Boston Mayor Thomas Menino -- and the Tucson survivors are lobbying for a bill that would require states to supply more complete mental health and criminal records to a federal database used for background checks on gun buyers.

The bill would also require federal background checks for those seeking to buy guns from private dealers, who often sell at gun shows. Now, purchases from private dealers are not subject to background checks.

Loughner legally purchased a gun from a licensed dealer even after college officials removed him from the school because of mental health issues. Loughner is in custody amid efforts to restore him to competency so he can stand trial.

"It's entirely possible Jared Loughner might not have bought the Glock" if his admission of drug use to the army or mental health problems were known, said New York Sen. Chuck Schumer, a Democrat, who led the subcommittee hearing. "I don't want there to be any more what-ifs."

Some mental health advocates worry the bill would unfairly punish those seeking mental treatment or discourage people from seeking treatment. A National Rifle Association spokeswoman did not immediately respond to a request for comment.

Gun control is a complex issue for the Tucson victims, some of whom own firearms and live in a conservative state that expanded gun rights after the January shooting. Giffords, a moderate Democrat, is known for her support of gun rights.

"I'm really distraught and pretty angry," Tucson shooting survivor Roger Salzgeber told Rep. Jeff Flake, a Republican from Arizona, in a meeting in Flake's office Tuesday afternoon.

Salzgeber helped subdue Loughner. His wife, Faith, wrapped a nine-year-old victim, Christina Taylor Green, in a tablecloth to keep her warm and comforted her as she lay on the ground dying from her wounds.

"I'm a gun owner. I've had my check done," Salzgeber told Flake. "I'm not here advocating to take anyone's guns away. I'm here to advocate that people who shouldn't have guns don't get guns."

Flake said he would look at the proposed bill.

The group of 12 survivors and their family members met with lawmakers the day after Giffords and her husband, astronaut Mark Kelly, appeared on national television for their first extended interview since the shooting.

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