UPDATE - 11:20 pm: Rep. Gabrielle Giffords of Arizona was shot in the head today when an assailant opened fire outside a grocery store during a meeting with constituents, killing at least six people and wounding several others.
Giffords was among at least 18 people wounded, and the hospital
says her outlook is "optimistic" and that she was responding to
commands from doctors.
The hospital says a 9-year-old girl was among those killed, and a U.S. Marshal says a federal judge was also fatally shot in the attack.
Giffords spokesman C.J. Karamargin says an unspecified number of her staff members were injured in the shooting.
Congressional officials say an aide to the Democrat was killed, and President Barack Obama says six people died in all.
U.S. Capitol police say the shooter is in custody.
Officials familiar with the investigation say the suspect claims he acted alone.
One official says the attack was carried out with an automatic
Giffords had just begun her third term.
The 40-year-old Democrat was re-elected in November, edging a tea party favorite.
She was a member of the Arizona House and Senate before coming to Washington.
Rep. Gabrielle Giffords, D-Ariz., was shot in the head and an aide was killed Saturday when an assailant opened fire in an area where the lawmaker was meeting with constituents, officials said.
Several others were shot in Pima County near Tucson today. At least four people are confirmed dead.
Initial reports by CBS Affiliate KOLD that the Congresswoman was among the fatalities were corrected by her press people, who told KOLD that she is alive but in surgery.
"She is currently in surgery. She is still alive," said Darcy Slaten, Public Affairs, University Medical Center in Tucson.
Eight others are being treated at the hospital as well.
The assailant reportedly sprayed bullets into an area where the Democratic lawmaker was hosting a "Congress on Your Corner" event at a Safeway supermarket.
A law enforcement source told CBS News that a man apparently stood up in the crowd during the town hall meeting, shouted something and then opened fire. Someone - possibly police or security - then shot at the gunman.
The gunman has been apprehended but it is unknown if he were wounded.
CBS News has learned that seven people are in the emergency room.
The FBI and local law enforcement are investigating the attack.
Giffords, 40, who just started her third term in Congress, was reelected in November after defeating Republican and Tea Party favorite Jesse Kelly by a margin 49 percent to 47 percent.
A moderate Democrat, Giffords has drawn the ire of the right, especially for her support of the health care bill. Shortly following her vote in favor of the health care reform law last March, her office in Tucson was vandalized, leaving the front door smashed.
According to her office, the "Congress on Your Corner" events allows residents of her district "to meet their congresswoman one-on-one and discuss with her any issue, concern or problem involving the federal government." Her office says she has hosted "numerous" events since taking office in 2007.
Following her swearing-in on Wednesday, the congresswoman introduced a bill to cut congressional salaries by five percent. Giffords was also among 19 Democrats who voted for someone other than Nancy Pelosi in Wednesday's vote for House Speaker. (She voted for Georgia Democrat John Lewis.)
She also participated in Thursday's reading of the Constitution on the House floor. She read the First Amendment, saying: "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof, or abridging the freedom of speech, or of the press, or of the of the people peacably to assemble, and to petition the government for the redress of grievances."
Her husband is Mark Kelly, an astronaut who is scheduled to command the Shuttle Endeavor when it launches in April. Her brother-in-law, Scott Kelly, is in charge of and currently aboard the International Space Station.
Statement from House Majority Leader John Boehner
Washington (Jan 8) - Speaker John Boehner (R-OH) issued the following statement condemning the attack on Rep. Gabrielle Giffords (D-AZ) and members of her staff today in Tuscon, AZ:
“I am horrified by the senseless attack on Congresswoman Gabrielle Giffords and members of her staff. An attack on one who serves is an attack on all who serve. Acts and threats of violence against public officials have no place in our society. Our prayers are with Congresswoman Giffords, her staff, all who were injured, and their families. This is a sad day for our country."
Statement from President Barack Obama
This morning, in an unspeakable tragedy, a number of Americans were shot in Tucson, 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 Representative 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. I ask all Americans to join me and Michelle in keeping Representative Giffords, the victims of this tragedy, and their families in our prayers.