Tucson: The US lawmaker shot in the head by a would-be assassin in a shooting spree remains critical but shows positive signs, medics said Sunday as prosecutors announced charges against the gunman.
Gabrielle Giffords, 40, was in a medically-induced coma but could respond to basic verbal commands, said doctors at the University of Arizona Medical Centre in Tucson, who were "cautiously optimistic" about her recovery chances.
A nine-year-old girl and a federal judge were among six people killed and at least 14 others were wounded before bystanders at the event in Tucson on Saturday grappled a gunman armed with a 9mm Glock pistol to the ground.
Alleged shooter Jared Loughner, a 22-year-old local resident, will appear in court in Phoenix on Monday and faces five charges including murder and attempted murder, Arizona`s district attorney Dennis K Burke said.
According to an affidavit, investigators found a letter from Giffords in a safe at Loughney`s home, dating from August 2007 and thanking him for attending a public meeting similar to the one on Saturday.
Also in the safe they found an envelope with "I planned ahead”, "My assassination" and "Giffords" written by hand on it, as well as what appeared to be Loughney`s signature, the affidavit said.
Giffords was helped by the fact the bullet did not go through both hemispheres of her brain, travelling instead the length of the left side of her brain, an area that controls speech.
"We`re very encouraged by that. We are still in critical condition. Brain swelling at any time can take a turn for the worse," said Michael Lemole, the head neurosurgeon who operated on Giffords.
Trauma chief Peter Rhee cautioned: "We don`t know what is going to happen -- what her deficits will be in the future or anything like that.”
"This wasn`t a grazing wound to the brain. This wound travelled the length of the brain on the left side," he said.
Giffords, from President Barack Obama`s Democratic Party, was meeting constituents outside a Tucson supermarket on Saturday when the gunman shot her at point blank range before spraying bullets on the small crowd.
The motivation for the shooting remained unclear. Loughner, a failed Army recruit, had filled the Internet with angry and largely incoherent condemnations of the government.
A Loughner profile posted on YouTube listed Karl Marx and Friedrich Engels`s "The Communist Manifesto" and Adolf Hitler`s "Mein Kampf" among his favourite books.
A witness who helped wrestle Loughner to the ground said it seemed the suspect had come ready to kill even more people because he had two more ammunition clips and a knife in his pockets.
"He was ready for war, he was not playing around," Joe Zamudio told CNN.
Pima county sheriff Clarence Dupnik said three bystanders tackled the shooter after he stopped shooting to reload his gun. A woman jumped on him at that point and tore an ammunition magazine away from him.
The gunman managed to reload with another magazine -- but a spring apparently failed, and then two male bystanders wrestled him to the ground, restraining him until police arrived.
If the gunman had managed to re-load and resume firing, "there would have been a huge catastrophe," said the sheriff.
Giffords, like most rank-and-file legislators, travelled with no security detail, despite threatening incidents during the recent bitter campaign that saw the Democrat re-elected in a typically Republican-leaning state.
Married to NASA astronaut Mark Kelly, Giffords is the first Jewish woman elected to Congress in Arizona. She barely survived a bruising re-election bid last year to a Republican rival from the right-wing Tea Party movement.
The attacks have shaken official Washington and -- although the motivations of the shooter are unclear -- raised concerns that the toxic political climate could be feeding violence.
The last major political shooting in the United States was in 1981 when then president Ronald Reagan was shot and injured at a Washington hotel.
Obama called on Americans to observe a "moment of silence" at 1600 GMT on Monday to honour the victims of the shooting.