The shooting of Gabrielle Giffords

US congresswoman Gabrielle Giffords, who was shot during a constituency event at a supermarket in Tucson, Arizona Photograph: Reuters

Giffords celebrates her victory in Arizona's 2006 congressional district election Photograph: David Sanders/AP

Giffords talks to a Tucson constituent Photograph: Reuters

Giffords meets constituents in Douglas Photograph: Reuters

Giffords and her husband, the astronaut Mark Kelly Photograph: Reuters

Giffords, seen on the right of the picture, with the former US president Bill Clinton Photograph: AP

The House Speaker, John Boehner, re-enacts the swearing-in of Giffords earlier this week Photograph: Susan Walsh/AP

Jared Loughner, who is in police custody in connection with the attack, pictured in the 2006 Mountain View high school yearbook Photograph: AP

A man identified as Jared Loughner, seen at the 2010 Tucson Festival of Books Photograph: Mamta Popat/Arizona Daily Star/AP

A law enforcement officer outside Loughner's home Photograph: Eric Thayer/Reuters

Two people comfort each other at the scene of the shooting Photograph: James Palka/AP

Police search the parking area outside the supermarket where the shooting happened Photograph: Kelly Presnell/AP

Police and residents of Tucson gather at the scene Photograph: Dean Knuth/AP

Emergency personnel outside the supermarket Photograph: Matt York/AP

A man places flowers outside the Giffords constituency offices Photograph: Matt York/AP

Tucson resident Leigh Harris leaves a candle at the vigil Photograph: John Moore/Getty Images

The US president, Barack Obama, issues a statement Photograph: Evan Vucci/AP

Greg Segalini holds a photo of his niece, Christina Green, the nine-year-old victim of the shooting, with his sister, Roxanna Green Photograph: Mark Henle/The Arizona Republic/AP

Judge John McCarthy Roll, killed in the shooting, testifies during a Senate judiciary committee hearing in 2006 Photograph: Mark Wilson/Getty Images