A police officer holds a modified gun that was turned in its owner at a gun buyback held by the Los Angeles Police Department in Los Angeles, California, Dec 26, 2012 following the mass shooting at Sandy Hook Elementary School in Connecticut. The program normally occurs in May but Los Angeles mayor Antonio Villaraigosa accelerated the schedule in response to the Dec 14 shooting that left 20 children and six adults dead, along with the gunman, and caused a national outcry against gun violence. People can anonymously trade in their guns, no questions asked, for $200 grocery store gift cards for automatic weapons and $100 gift cards for shotguns, handguns and rifles. [Photo/Agencies]

Hand guns that were turned in by their owners are seen in a trash bin at a gun buyback held by the Los Angeles Police Department following the mass shooting at Sandy Hook Elementary School in Connecticut, in Los Angeles, California, Dec 26, 2012. [Photo/Agencies]