Washington - 12:09 p.m. Kelly says he would give up his right to own a high-capacity magazine in order to bring back Christina-Taylor Green, the 9-year-old girl killed in the Tucson shooting.
12:04 p.m. LaPierre says Americans are afraid that "they will be abandoned by their government. The only way they can protect themselves ... is with a firearm." Johnson, the police chief, is asked to respond. He says law enforcement is "well prepared" to deal with any disaster. "I can't relate to that kind of thinking," Johnson says about LaPierre's statement.
12 p.m. Durbin says there should have been a hearing like this after Giffords was shot, but he said it took the Newtown incident to get to this point.
11:56 a.m. After hearing statistics on gun violence, LaPierre of the NRA says it is tragic. "We've got to interdict these people and get them off the streets," he says. "Problem with gun laws is criminals don't cooperate with them. The mentally ill don't cooperate with them." He repeats his stance against proposed universal background checks.
Sen. Richard Durbin, D-Ill., refutes LaPierre's testimony and Leahy bangs his chairman's gavel to restore order in the hearing.
11:52 a.m. Cornyn asks Kelly about people with mental illness in Arizona whose applications for guns were denied. Kelly refutes a point made earlier by LaPierre, the NRA chief. About Loughner: "His plan was to assassinate my wife. He was a criminal because of his drug use," Kelly says. "He would have failed that (gun) background check."
Kelly says Giffords would not have been at the Senate hearing on Wednesday "if we had stronger background checks."
11:47 a.m. Johnson, the Baltimore County police chief, says comprehensive background checks are "not inconvenient."
11:44 a.m. Sen. Charles Schumer, D.-N.Y., says he is in discussions with legislators who have "high NRA ratings" on bipartisan legislation to reduce gun violence. He says he can't share details. "It won't create any gun registry. That is already illegal. It will not limit your ability to borrow your Uncle Willie's hunting rifle," Schumer says.
11:38 a.m. LaPierre says crime would be reduced if laws already on the books are enforced. "The numbers are shocking," he says.
11:33 a.m. Sen. Jeff Sessions, R-Ala., a former prosecutor, criticizes the Obama administration's record on prosecuting gun crimes.
11:29 a.m. Feinstein asks what can be done to prevent gun violence at shopping malls, theaters and other businesses.. "We can't have a totally armed society," the senator says. She asks Chief Johnson if the legislation proposed would be effective. He says: "Yes, ma'am, I do."
11:24 a.m. Feinstein, the California Democrat and author of a proposed assault weapons ban, makes a joke that it's good to see LaPierre, the NRA's CEO. She notes they tangled during the 1994 battle over the weapons ban. "You look good," she said.
11:15 a.m. Grassley questions Kopel, the Denver law professor, about the effectiveness of the 1994 assault weapons ban. "It was tried with great sincerity ... but it didn't seem to save any lives that the researchers could find," Kopel said.
11:11 a.m. LaPierre says "straw man" gun sales should be prosecuted -- such as anyone who helps a criminal get a gun. But he says it does no good to extend background checks to private sellers or in all instances. "The fact is the law right now is a failure the way it is working," LaPierre says. "This administration is not prosecuting the people they catch."
11:09 a.m. Question goes to Kelly. He says there is more that can be done on background checks. He notes that Jared Loughner, the shooter in the Tucson massacre that wounded Giffords, purchased a gun with a background check. "This is one of the most important things we must do," he said. "Requiring private (gun) sellers to have a background check before they transfer a gun ... I can't imagine something more important" than requiring that.
11:06 a.m. The formal statements are over and questioning of the witnesses has begun. Leahy asks Chief Johnson about the effectiveness of background checks.
11:04: More from LaPierre's testimony: "Proposals that would only serve to burden the law-abiding have failed in the past and will fail in the future." He said studies show the 1994 assault weapons ban did not reduce crime. "And when it comes to the issue of background checks, let's be honest -- background checks will never be universal because criminals will never submit to them," he says.
11:02 a.m. LaPierre says "proposing new gun laws, while failing to enforce the thousands we already have, is not a serious solution to reducing crime."
"Law-abiding gun owners will not accept blame for the acts of violent or deranged criminals. Nor do we believe the government should dictate what we can lawfully own and use to protect our families," the NRA chief says.
11 a.m. LaPierre says NRA does more "than anyone else on teaching safe and responsible gun ownership." He explains former congressman Asa Hutchinson's role in developing a school safety program. "It's time to throw an immediate blanket of security around children," he says.
10:58 a.m. Now up, Wayne LaPierre, CEO of the National Rifle Association.
10:57 a.m. Trotter calls for "sensible" enforcement of the gun laws already on the books. "Instead of self-defeating gestures, we should address gun violence based on what works," she says. "For women, the ability to arm ourselves is even more consequential than for men. Guns are the great equalizer."
10:54 a.m. Now testifying: Gayle Trotter, a lawyer and senior fellow at the Independent Women's Forum. She talks about violence against women and research on concealed carry laws. "Armed security works," Trotter says.
10:53 a.m. Giffords just sent a tweet, quoting from her husband's testimony: "The breadth and complexity is great, but it is not an excuse for inaction."
10:46 a.m. Now testifying: James Johnson, chief of Baltimore County (Md.) Police Department. He says law enforcement leaders back Obama's approach to reducing gun violence. "I'm here today to tell you we are long overdue in strengthening our nation's gun laws," he says. Johnson calls for background checks and says law enforcement groups support the assault weapons ban proposed by Sen. Dianne Feinstein, D-Calif. Johnson also says states need help dealing with gun trafficking across state lines. He says high capacity ammunition magazines are not necessary for hunting.
10:42 a.m. Now testifying: David Kopel, a professor at Denver University's law school. He's going through the history of congressional statutes on guns. "Universal background checks should be available," Kopel says. "Mandating universal checks can only be enforceable if there is universal gun registration."
10:39 a.m. Kelly says Congress should close the gun show loophole and enact a tough federal gun trafficking statute. Kelly says Congress should not look to ideology but try to compromise.
10:35 a.m. "We believe in the Second Amendment. We take that right seriously and we would never give it up. But rights demand responsibility and this right does not extend to terrorists...to criminals ...to the mentally ill. When dangerous people get dangerous guns, we are all the more vulnerable," Kelly says.
10:33 a.m. Kelly says he and Giffords "aren't here as victims. We're speaking to you today as Americans. We're both gun owners and we take that right and the responsibilities that come with it very seriously."
10:32 a.m. First witness is Mark Kelly, a retired astronaut and Giffords' husband. The couple have founded Americans for Responsible Solutions, a PAC aimed at reducing gun violence.
10:27 a.m. Grassley criticizes executive actions taken by Obama to reduce gun violence, saying there is not enough detail provided about the specifics of each move. He also says they could have been issued before Newtown.
10:24 a.m. Grassley says any discussion about what to do needs to include focus on mental health. He also condemns violent video games. "Banning guns based on their appearance does not make sense," Grassley says about proposed assault weapons ban. He also questions limit on ammunition magazines.
10:21 a.m. Grassley, the top Republican on the committee, is now speaking. He says no one will ever forget where they were when they learned about the "evil act" that happened at Newtown. "Clearly violent crimes and those who commit them are a plague on our society," he says.
10:17 a.m. Leahy says "Americans are looking to us for solutions and for action."
He says it is a "simple matter of common sense" to plug loopholes in the law dealing with background checks for gun owners.
"The Second Amendment is secure and will remain secure and protected," Leahy says.
10:15 a.m. Leahy begins his opening statement, saying "America's heart was broken" on Dec. 14 when 20 children and six educators were killed at Sandy Hook school in Newtown, Conn.
"I hope we can forgo partisan recrimination. It's too important for that. We should all be here as Americans."
10:12 a.m. Giffords is speaking haltingly, slowly enunciating her words. "This is an important conversation for our children," she says. "Speaking is difficult but I need to say something important Violence is a big problem. Too many children are dying. ... It will be hard but the time is now. You must act. Be bold. Be courageous. Americans are counting on you. Thank you."
10:11 a.m. Leahy lays down the rules for the hearing, asking for respect on this "serious subject." Capitol police will remove anyone who is disorderly. "We're going to hear a lot of different perspectives on gun violence," he says.
10:09 a.m. Giffords and Kelly are being escorted to the witness table by Leahy and Grassley. The photographers are snapping away.
10:01 a.m. ET Before the hearing, Giffords sent out a tweet thanking Senate Judiciary Chairman Patrick Leahy, D-Vt., and Sen. Chuck Grassley, R-Iowa, "for starting this conversation."