Prosecutors accused Jared Lee Loughner, a troubled 22-year-old college dropout, of five serious federal charges on Sunday, including the attempted assassination of a member of Congress, for his role in a shootout that left 20 people wounded, six of them fatally, on Saturday morning.
According to court documents filed in the U.S. District Court in Phoenix, the authorities seized evidence from Loughner's home showing that he had planned to kill Rep. Gabrielle Giffords, who was in critical condition on Sunday with a gunshot wound to the head. Tony Tayler Jr., an FBI special agent, said in an affidavit supporting the charges that an envelope was found there with the handwritten words, "I planned ahead," "My assassination," and "Giffords."
Other details about the envelope were not disclosed.
The court documents say that Loughner purchased the semiautomatic Glock pistol used at the shooting at Sportsman's Warehouse in Tucson on Nov. 30. The documents also indicate that the suspect had previous contact with the congresswoman: The authorities found a letter from Giffords thanking Loughner for attending a 2007 "Congress on Your Corner" event, similar to the one she was holding on Saturday morning when she was attacked.
Along with being accused of deliberating trying to take Giffords' life, Loughner was charged with killing or attempting to kill four other U.S. government officials: U.S. District Judge John M. Roll and Gabriel Zimmerman, an aide to Giffords, who were killed; and two other congressional aides, Pamela Simon and Ron Barber, who were wounded.
The shooting of the 15 other people who were wounded or killed in the attack would be state crimes rather than federal crimes; as of Sunday afternoon no state charges had yet been filed.
The director of the FBI, Robert Mueller, who traveled to Tucson from Washington to oversee the shooting investigation at President Barack Obama's request, said at a news conference that agents were working intensively to determine, "why someone would commit such a heinous act and whether anyone else was involved."
Early Sunday, the authorities released a photograph taken from surveillance video of a possible accomplice in the shooting. But the man later contacted sheriff's deputies, who determined that he was a taxi driver who dropped the suspect at the mall where the shooting took place and then entered the supermarket with him when he did not have sufficient change.
Giffords, an Arizona Democrat, remained in critical condition at University Medical Center in Tucson on Sunday. Her doctors said she was able to respond to simple commands and they described themselves as "cautiously optimistic."
At a news conference at University Medical Center, the congresswoman's doctors said that she was the only one of the victims of Saturday's shooting who was still in critical care. They said that she was lucky to be alive, but would not speculate about the likely course of her recovery, which they said could take months or longer.
"Overall this is about as good as it's going to get," said Dr. Peter Rhee, the chief of trauma surgery at University Medical Center, where Giffords was brought by helicopter from the shooting scene. "When you get shot in the head and a bullet goes through your brain, the chances of you living are very small and the chances of you waking up and actually following commands is even much smaller than that."
The doctors said that Giffords, 40, was in a medically induced coma but that they woke her several times to check her responsiveness. While the doctors described themselves as extremely pleased with the progress of her treatment, they cautioned that it was too soon to make any predictions.
As the doctors provided the update Sunday, law enforcement authorities tried to piece together what prompted a troubled young man to go on a shooting rampage.
At a news conference, Sheriff Clarence Dupnik of Pima County described a chaotic scene of terror and heroism as the shots rang out. He said one woman who was injured in the shooting fought to wrestle a magazine of ammunition away from the gunman as he tried to reload. He succeeded in reloading, the sheriff said, but was then tackled by bystanders. Officials, who did not name the woman, said the attack could have been more devastating had she not tried to stop the man.
The authorities have not asserted any specific motivation for the shootings other than to say that Giffords was clearly the intended target.
Loughner, who was in federal custody, refused to cooperate with investigators and invoked his Fifth Amendment rights on Saturday, the Sheriff's Office said. Loughner had exhibited increasingly strange behavior in recent months, including ominous Internet postings — at least one showing a gun — and a series of videos in which he made disjointed statements on topics like the gold standard and mind control.
Pima Community College said he had been suspended for conduct violations and withdrew in October after five instances of classroom or library disruptions that involved the campus police.
Mueller, the FBI director, said that possible links to extremist groups would be a continued focus. "The ubiquitous nature of the Internet means that not only threats, but hate speech and other inciteful speech is much more readily available to individuals than quite clearly it was eight or 10 or 15 years ago," Mueller said.
The words echoed comments by Pima County Sheriff Clarence Dupnik, who said Saturday at a news conference that "unbalanced people" could be affected by the vitriol, anger and hatred of antigovernment rhetoric.
Loughner's friends and acquaintances said he was left isolated by his increasingly erratic behavior — apparently exacerbated by drug use, as a military official said Sunday that he had failed a drug screening.
Lydian Ali, 26, a classmate at Pima Community College, said, "He would laugh a lot at inappropriate times, and a lot of the comments he made had no relevance to the discussion topic."