A 22-year-old man has made his first appearance in an American court on various charges, including the attempted assassination of US representative Gabrielle Giffords.
College dropout Jared Lee Loughner said he understood the charges as they were read out to him and the judge scheduled a preliminary hearing for January 24.
At his court appearance, Loughner's lawyer waived a detention hearing. Federal Magistrate Judge Lawrence Anderson ordered Loughner held, calling him a danger to the community.
The rampage took place at an event Giffords was hosting for constituents. The shooting spree in Tucson left six people dead and 14 others wounded.
One of those who died was a nine-year-old girl who had been born on September 11th 2001 - the day of the terror attacks.
Last year, Gabrielle Giffords had warned that angry campaign talk had prompted violent threats against her and vandalism at her office.
This latest round of deadly violence has fueled the debate about whether heated rhetoric in recent US political campaigns can prompt people to take their own action.
A police mug shot taken of Loughner after his arrest shows the accused killer, who faces a possible death sentence, smiling broadly.
Giffords was shot at point-blank range in the head. The 40-year-old remains in a critical condition at Tucson hospital.
Doctors said there was no increased swelling of her brain and she continued to respond to simple commands such as squeezing a finger and wiggling her toes.
"There have been no complications," Dr Peter Rhee of University Medical Center in Tucson said: "We're happy with where we are. But we have to give her some time to see how she's going to do."
A single bullet passed through her brain on the left side, hitting an area that controls speech. The extent of brain damage she may have suffered is uncertain.
A minute's silence was held on Monday as the nation mourned the dead. Barack and Michelle Obama led the poignant tribute at the White House.
A bell tolled three times as an estimated 300 staffers offered their respects.
"Right now the main thing we're doing is to offer our thoughts and prayers to those who've been impacted, making sure that we're joining together and pulling together as a country," Obama said.
President Obama plans to go to Arizona on Wednesday to attend a memorial service for the dead.