Pima County Sheriff Clarence Dupnik said Arizona U.S. Rep. Gabrielle Giffords was the intended target in the shooting and he described suspect Jared Loughner as one with a criminal record and one with mental issues. Dupnik also said he was "not convinced" that the suspect acted alone, but he declined to elaborate.
Giffords, 40, a third-term Democrat, was shot through the head at shortly after 10 a.m. Saturday morning at a Safeway at Ina and Oracle roads in northwest Tucson. Loughner, 22, is currently in custody. (Initial news accounts and reports from authorities misidentified the name as Laughner.)
Giffords has undergone brain surgery after being shot by a man who opened fire with a handgun when the Congresswoman was holding a public appearance in Tucson.
One of the surgeons who operated on Giffords said afterwards, "I'm very optimistic about her recovery."
Six people were killed, including U.S. District Judge John Roll, a Giffords aide and a young girl, and 19 others were wounded in the shooting, authorities said. The aide was identified as Gabe Zimmerman, 30, Giffords' community outreach director; he was engaged to be married.
Neurosurgeons at the University Medical Center in Tucson operated on Giffords and doctors were hopeful she would recover, Dr. Peter Rhee said during a news conference at the hospital.
Giffords was following commands, a good sign, he said.
The bullet entered one side of Gifford's head and exited the other after passing through her brain, he said.
"She was shot one time in the head through and through," Rhee said.
Authorities had pursued the possibility of at least one other suspect early on in the investigation. They mentioned that Loughner did not appear to have driven to the area and may have been dropped off or taken other modes of transportation.
Initial reports had emergency crews treating five to seven people at the scene; authorities said later the tally was much higher because some of the wounded took themselves to the hospital.
The first 911 call came in at 10:11 a.m. The gunman opened fire with a pistol with an extended magazine.
The NBC affiliate in Tucson reports that the FBI has taken over the investigation.
Police have blocked off the street where Loughner lives in an older neighborhood of modest ranch houses in the northern part of Tucson. Sheriff's deputies and FBI agents have been there and were standing guard outside.
Two police cars were parked in front of Loughner's house. Police wrapped caution tape to prevent anyone from getting near the house. Neighbors were shocked by the shooting.
"This is not a bad neighborhood. When something like this happens, it hits too close to home," said Jim Berger, who lives around the corner from Loughner.
Grant Wiens, 22, who lives in the neighborhood, said he attended Mountain View High School in Tucson with Loughner and then Pima Community College. He brought out his 2006 yearbook with Loughner's photo.
In the photo, Loughner has long curly hair to his shoulder.
Wiens described Loughner as "kind of an interesting character" who kept to himself.
Wiens said he hadn't talked with Loughner much, but that he seemed opinionated.
Another neighbor Ryan Miller, 19, said he also attended Mountain View High School and knew Loughner slightly.
"He just seemed like a normal, everyday kid to me. I'm extremely shocked."
Asked what kind of group the suspect hung out with, he said "I would see him more as a jock, hanging out with the sporty kids."
Tyler Ramsier, 24 graduated from Mountain View High School one year before Loughner. He described Loughner as someone who kept to himself and hung out with a small group of friends. He said Loughner sometimes wore a trench coat and often dressed in dark clothes like those worn by people into "goth" culture.
Jeff Shope also went to Mountain View High School with Loughner.
"I was shocked. I never thought this would happen. It really hits home," Shope said.
According to a Pentagon statement, the Army has confirmed that the suspect was never in the Army. He attempted to enlist in the Army but was rejected for service. In accordance with the Privacy Act, the Pentagon would not discuss why he was rejected.
The shooting rocked the shopping area in the northwest Tucson neighborhood.
Ryan Green, who works at the Pak Mail shipping store in the Safeway shopping center, said he heard 15 shots a few minutes after 10 a.m. Green said he waited for the shooting to stop before he went outside to see people on the ground."It was pandemonium," Green said.
Green rushed back into the shop, locked the door and waited for police to arrive, he said.
A man who works at Sprint store nearby told CNN he heard 15 to 20 shots, and there are two bodies on the ground in front of the Safeway. He said people were screaming that "Gabrielle Giffords has been shot."
Rhee the University Medical Center surgeon said neurosurgeons had finished operating on Giffords and she was under anesthesia. She was being taken to intensive care. Rhee said he would know better in 24 hours what the prognosis is.
He said the congresswoman was following commands, a good sign, he said.
DDeputy Director Ron Barber was also injured in the shooting but was OK, said C.J. Karamargin, Giffords' communications director, who was not at the event. Another staffer, Pam Simon, was also hit, Karamargin said, but she will also be OK.
"Gabby is a tough as they come, and I am hopeful she is going to come through," President Barack Obama said during a news conference in Washington. "It is a tragedy for Arizona and a tragedy for the entire country."
Obama said he had called Arizona Gov. Jan Brewer and offered the full resources of the federal government and promised investigators would get to the bottom of the shooting.
"We don't know yet what provoked this unspeakable act," Obama said.
Brewer appeared visibly shaken at a news conference as she said "I am just heartbroken."
Brewer said she has ordered flags in Arizona to be flown at half staff. She called the shooting "an unbelievable tragedy" for the people of Arizona. She called Giffords a friend.
"I've grown to love and respect her. She never really played partisan politics. She was serious about her work," Brewer said. "She is a very gracious public servant."
Brewer was asked if how the shooting reflected on Arizona.
"It certainly doesn't show favor on the state of Arizona, but we have a lot of good decent people here," Brewer said.
On Saturday afternoon, about 60 to 70 people had gathered outside Giffords' office on Swan Road in Tucson.
The mood was somber. At one point 35 people held hands in a circle, as motorists drove by honking in support. People were getting information from texts and mobile devices. At times they sang "Give Peace a Chance."
Among the wounded in Saturday's shooting were two Giffords staffers who were expected to recover: Ron Barber, Giffords' district director; and Pam Simon, a community outreach worker.
Saturday's event was Giffords "Congress on Your Corner" event of the year.
The meetings allow residents of Arizona's 8th Congressional District to meet Giffords one-on-one.
Giffords usually holds the meetings with members of her staff, and the events have drawn as many as 150 people.
Giffords tweeted this just as her event at Safeway was beginning:
"My 1st Congress on Your Corner starts now. Please stop by to let me know what is on your mind or tweet me later."
Obama called the shooting in a statement an "an unspeakable tragedy."
"We do not yet have all the answers. What we do know is that such a senseless and terrible act of violence has no place in a free society. I ask all Americans to join me and Michelle in keeping Representative Giffords, the victims of this tragedy, and their families in our prayers," Obama said.
In November, Giffords a moderate Democrat, won re-election to her third 2-year term, narrowly escaping defeat to Republican businessman Jesse Kelly in a contentious race that centered largely on the issue of illegal immigration and border security, two hot button issues in southern Arizona.
Although immigration and border security played a role in every major race in the state, the debate was especially fierce in the 8th Congressional District. The District includes a 114-mile stretch of the U.S. border
During the campaign, Giffords touted her efforts to push the Obama administration to deploy National Guard troops to the border and for playing an instrumental role in securing $600 million in funding to add more technology and Border Patrol agents.
Kelly criticized Giffords for not doing enough and had called for the construction of a double-layer border fence, more Border Patrol agents and the deployment of 10,000 National Guard troops to the border, more than eight times the 1,200 sent by the Obama Administration. At one point during the heated campaign, Kelly had said Giffords had "betrayed southern Arizona by refusing to secure the border."
Giffords opposed SB 1070, the state's new controversial immigration law, calling it "divisive." She supported instead comprehensive immigration reform at the federal law. The law sought to make it a state crime to be in the country illegally and to require police to question suspected illegal immigrants. Kelly supported the law, and opposed sweeping reforms in favor of stricter enforcement of existing laws.
Giffords serves on the House Armed Services Committee.
She is married to Mark Kelly, an astronaut. She has two step daughters Claudia and Claire Kelly.
Before Giffords was elected to Congress, she was president and CEO from 1996-2000 of her family's southern Arizona tire business, El Campo Tires.