Congresswoman Gabrielle Giffords Shot in Tucson-1294516369924-jpg

Judge John Roll was killed and U.S. Rep. Gabrielle Giffords was critically wounded in a shooting rampage Saturday at a shopping plaza in Tucson, Arizona, President Barack Obama said in a televised statement Saturday evening.

"We are still assembling all the facts, but we know that Representative Giffords was one of the victims," Obama said. "She is currently at a hospital in the area, and she is battling for her life.

"We also know that at least five people lost their lives in this tragedy. Among them were a federal judge, John Roll, who has served America's legal system for almost 40 years; and a young girl who was barely 9 years old."

Giffords, who represents Arizona's 8th Congressional District, was holding a public meet-and-greet event outside of a supermarket when the shooting began. She was listed in critical condition at University Medical Center in Tucson, although several news outlets had reported earlier in the day that she had died.

"I am about as optimistic as it can get in this situation," Dr. Peter Rhee of the medical center said about Giffords' prospects for recovery. He said she had been struck by one bullet, in the head, and that the bullet had passed through her brain. Dr. Rhee also said the medical center was treating five people who were in critical condition and five people who were in surgery.

In a brief statement just before the hospital news conference, a spokesman for the Pima County Sheriff's Department said that six people had been killed and 12 wounded when a gunman opened fire about 10:15 a.m. Giffords, a 40-year-old Democrat, was rushed to the medical center, according to KVOA television. She was reportedly talking to a couple when a man ran up, began shooting, then fled on foot before being tackled by a bystander and taken into custody.

The Associated Press reported that Jared Loughner, 22, was being held Saturday in connection with the shooting. And CNN, citing law enforcement sources, said that a 9-milimeter handgun had been recovered.

The scene of the shooting was chaotic and the shopping center was shut down as law enforcement authorities investigated.

Ken Penner, who works in the area, told KOLD television that he had seen Giffords speaking to an elderly couple and that about 15 or 20 people had been waiting to speak with her. He had just entered the Safeway store when the shooting started, he said, and customers began running toward the back of the store. When he looked out after the shooting stopped, he said he saw Gifford lying on the ground, motionless.

President Obama said in a statement: "This morning, in an unspeakable tragedy, a number of Americans were shot in Tuscon, Arizona, at a constituent meeting with Congresswoman Gabrielle Giffords. And while we are continuing to receive information, we know that some have passed away, and that Rep. Giffords is gravely wounded. 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."

Speaker John Boehner released a statement saying he was horrified about the shooting. "An attack on one who serves is an attack on all who serve," Boehner said, adding, "This is a sad day for our country."

House Minority Leader Nancy Pelosi called the attack a "national tragedy and a very sad day for our country." Giffords, Pelosi said, is a "brilliant and courageous member of Congress."

Senator John McCain, Republican of Arizona, issued a statement saying, "Whoever did this; whatever their reason, they are a disgrace to Arizona, this country and the human race, and they deserve and will receive the contempt of all decent people and the strongest punishment of the law."

Giffords' rabbi, Stephanie Aaron, told KOLD in a telephone interview, "I don't understand how something like this can happen in our town, in our state and in our country."

The Brady Campaign to Prevent Gun Violence issued a statement that said in part: "We find it unacceptable that when Americans and our elected leaders are assembling in public places, their lives are at risk from gun violence. We also are deeply concerned about the heated political rhetoric that escalates debates and controversies, and sometimes makes it seem as if violence is an acceptable response to honest disagreements."

Giffords, who was elected in November to a third term, was holding an event called "Congress on Your Corner" outside a Safeway store in a shopping center at the intersection of Ina and Oracle streets in Tucson. The congresswoman routinely makes herself available for one-on-one conversations with constituents, typically in front of supermarkets on Saturday mornings. But this was the first she had held since her re-election.

Giffords, generally regarded as a centrist on Capitol Hill, was criticized by some in Arizona for her support of the health care reform law. A few hours after the House vote on the health care bill, her office in Tucson was vandalized. She has called Arizona's tough anti-illegal immigration law "divisive" and said it did not make her district safer. But Giffords did not back the boycott of Arizona businesses that was supported by some opponents of the law.

Earlier this week, Giffords participated in the reading of the Constitution on the floor of the House of Representatives. She read the First Amendment, according to The New York Times.

"I wanted to be here, I think it's important," The Times quoted Giffords as saying. "Reflecting on the Constitution in a bipartisan way is a good way to start the year."

KOLD reported that Giffords is a gun owner and a supporter of gun rights. The station also said she was known for riding her Harley Davidson motorcycle to events.

Giffords, who has served in Congress since January 2007, is an Arizona native and a graduate of Cornell University. She married Cmdr. Mark E. Kelly, a NASA astronaut who is based in Houston, on Nov. 10, 2007.

Judge Roll was the chief judge of the U.S. District Court for Arizona, a post he had held since 2006. He was at the center of Arizona's immigration debate, according to The Washington Post, and faced death threats in 2009 after he allowed a lawsuit by illegal immigrants against a rancher to move forward. He had also been an Arizona state appeals court judge and a former assistant U.S. attorney in Arizona.