WASHINGTON — Former congresswoman Gabrielle Giffords, who was herself a victim of a mass shooting in Tucson, opened the Senate Judiciary Committee's hearing Wednesday with a call to action on gun violence.

"Speaking is difficult but I need to say something important," she said in a slow, deliberate voice. "Violence is a big problem, too many children are dying, too many children. We must do something. Americans are counting on you," she said.

The hearing exposed differences of opinion among legislators, gun control supporters and gun-rights groups and organizations. Topics included a proposed assault weapons ban, mental health and crime, the proposed expansion of federal background checks to buy guns was the most-discussed measure.

Senators on both sides were very careful to avoid saying anything that could be seen as personally insulting the victims of gun violence — Several members on the panel noted the presence of families of victims of various shootings, including Sen. Richard Blumenthal, who drew attention to the family of a Newtown victim. Time after time, the senators and witnesses seemed to back down from confrontation.

Mark Kelly, left, listens as Wayne LaPierre, right, National Rifle Association Chief Executive Officer, testifies before the Senate Judiciary Committee hearing on gun violence on Capitol Hill in Washington, Wednesday, Jan. 30, 2013. (AP Photo)

Here are some of the key things people said at the hearing about background checks:

"We must come together today as Americans seeking common cause. Let us forgo sloganeering, demagoguery and partisan recriminations, this is too important for all that."

—Senate Judiciary Chairman Patrick Leahy, D-Vt.

"When it comes to background checks, let’s be honest. Background checks will never be universal because criminals will never submit to them."

— Wayne LaPierre, CEO of the National Rifle Association.

"Mr. LaPierre, that’s the point. The criminals won’t go to purchase the guns because there will be a background check."

— Sen. Dick Durbin, D-Ill.

"It (Universal Background Checks) won't create any gun registry. It will not limit your ability to borrow your Uncle Willie's hunting rifle."

— Sen. Charles Schumer, D.-N.Y.

"The best way to stop a bad guy from getting a gun in the first place is a good background check."

— Baltimore County Police Chief James Johnson

"We’d like to see the federal laws that are on the books enforced."

— Sen. Jeff Sessions, R-Ala.