The U.S. Conference of Mayors -- led by Democratic Mayor Michael Nutter of Philadelphia -- is calling on President Obama and Congress to enact stronger gun laws, appoint a commission to examine violence in the nation and supply "adequate" funding for mental health.
"Too many times this year, mayors have expressed shock at a mass shooting," the mayors said in a letter. "Even more frequently, many of us must cope with the gun violence that occurs on the streets of our cities."
The letter to Obama and Congress asks Obama to use his office to introduce legislation to make "reasonable changes in our guns laws," and to support legislation to ban assault weapons and other high-capacity magazines being prepared by Senator Dianne Feinstein.
They also ask for strengthening the national background check system and eliminating loopholes and for strengthening the penalties for straw purchases of guns.
A citizen-generated petition on the White House site, We The People, has gathered nearly 200,000 signatures in support of "a bipartisan discussion resulting in a set of laws that regulates how a citizen obtains a gun."