Rep. Gabrielle Giffords (D-Ariz.) attended a candlelight vigil on Sunday marking the one-year anniversary of the 2011 shooting that critically injured her and left six others dead.

Giffords led the crowd at the memorial ceremony in Tucson, Ariz., in the Pledge of Allegiance, according to reports.

Giffords, who was shot in the head when a gunman opened fire during an event with constituents last January, has regained the ability to walk and speak after months of therapy. 

Reports said that the crowd chanted "Gabby, Gabby." 

The remembrance ceremony at the University of Arizona was the culmination of an emotional week for the congresswoman and her husband, retired Navy Capt. Mark Kelly.

The day began with a bell-ringing ceremony at 10:11 a.m. the exact time a year ago when a gunman opened fire in a Safeway parking lot where Giffords was hosting an event with constituents. The gunman shot 19 people, including the congresswoman.

Jared Lee Loughner, the man accused by the federal government of the shooting, is still in custody awaiting trial.

Earlier in the day, President Obama spoke with Rep. Giffords and told her she was an "inspiration" to the nation. Obama told Giffords that he and the first lady still mourn the victims of the shooting and have kept them and their families in their thoughts and prayers.

The president praised her "courage and determination," according to a White House readout of the phone call.

Giffords, who has expressed interest in returning to Congress, has not said if she will run for reelection in 2012. 

House Democratic leaders have said there is no timeline for her to decide whether she will run again, but have cleared the field for Giffords if she decides to run for her House seat or contest the Senate seat to be vacated by the retiring Sen. Jon Kyl (R-Ariz.).