Tucson shooting: One year later

Rep. Gabrielle Giffords and her husband, Mark Kelly, sit together at the start of a memorial vigil.  (Ross D. Franklin / Associated Press)

People hold up lights during a a memorial vigil for the victims of the Tucson shootings one year ago.  (Matt York / Associated Press)

Rep. Gabrielle Giffords, right, is embraced by Pam Simon, one of those wounded in the shootings a year ago.  (Ross D. Franklin / Associated Press)

Ron Barber, a Gabrielle Giffords aide who was wounded in last year’s shootings, speaks at the memorial while the audience holds up glow sticks.  (Jonathan Gibby / Getty Images)

Rebecca Kraft, 4, places flowers Sunday at a memorial in a Safeway parking lot in Tucson, Ariz., for the six people who lost their lives in a deadly shooting at the grocery store last year.   (Jonathan Gibby / Getty Images)

Residents ring bells Sunday in a memorial ceremony for the six people who died in a shooting last year in Tucson, Ariz., that also wounded U.S. Rep. Gabrielle Giffords.  (Jonathan Gibby / Getty Images)

Sherrie Brown, an employee of the Safeway where U.S. Rep. Gabrielle Giffords was shot on Jan. 8, 2011, is comforted by Leroy Wood during Sunday’s memorial for the six people who died in the shooting.   (Jonathan Gibby / Getty Images)

Crosses on the highway in Tucson, Ariz., serve as reminders of the six people who lost their lives in a deadly shooting in a nearby Safeway grocery store.   (Jonathan Gibby / Getty Images)

A plaque on a boulder outside the La Toscana Village Safeway in Tucson, Ariz., commemorates the Jan. 8, 2011, shooting there that killed six people and wounded 13, including U.S. Rep. Gabrielle Giffords.   (Jonathan Gibby / Getty Images)