Former Rep. Gabrielle Giffords, D-Ariz., at a firing range in Nevada earlier this week. Her husband, retired astronaut Mark Kelly, was behind her. Americans for Responsible Solutions hide caption

itoggle caption Americans for Responsible Solutions

None of the possibly ricin-tainted letters mailed to President Obama have reached the White House, authorities say. They were intercepted at a remote mail handling facility. Larry Downing /Reuters /Landov hide caption

itoggle caption Larry Downing /Reuters /Landov

Detective Enrique Chavez logs weapons from a gun buyback in Miami. Arizona's new law requires municipalities to re-sell weapons recovered in such programs. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images

Francine Wheeler, seen here delivering the presidential address alongside her husband, David, urged the Senate to pass gun control legislation. YouTube hide caption

itoggle caption YouTube

This AR-15 style weapon was on display in March at the 7th annual Border Security Expo in Phoenix, Ariz. It's among the type of weapons that advocates of new gun laws want to see banned. Joshua Lott /Reuters /Landov hide caption

itoggle caption Joshua Lott /Reuters /Landov

A Bushmaster rifle, similar to the type used by Adam Lanza during the shooting at Sandy Hook Elementary School, and some ammunition magazines. The sale and possession of this type of weapon, and high-capacity magazines, will be severely restricted in Connecticut under new legislation. Michelle McLoughlin /Reuters /Landov hide caption

itoggle caption Michelle McLoughlin /Reuters /Landov

Chris Colwell, director of emergency medicine at Denver Health, has treated victims from two of the deadliest mass shootings in the U.S. He says he's deeply disturbed by how easy it is to get guns. Barry Gutierrez/for NPR hide caption

itoggle caption Barry Gutierrez/for NPR

Vice President Biden at a December 2012 meeting of police chiefs on gun control, held in Washington, D.C. Carolyn Kaster/AP hide caption

itoggle caption Carolyn Kaster/AP