JEFFREY BROWN: Today marked six months since the massacre in Newtown, Conn., an attack that brought tears and outrage and prompted a new debate over gun violence and rights.
Margaret Warner has a look at how the day was commemorated.
CARLEE SOTO, Sister of Victoria Soto: If we can take that moment now, please?
MARGARET WARNER: The sister of slain teacher Victoria Soto asked for twenty six seconds of silence today, one for each of the victims killed at Sandy Hook Elementary School.
They were gunned down on Dec. 14, after Adam Lanza killed his mother and then stormed Sandy Hook. Police said Lanza shot 20 schoolchildren and six educators, before shooting himself. Today's moment of silence was followed by a daylong reading of more than 6,000 names, all victims of gun violence around the country since the Newtown tragedy.
The memorial was organized by Mayors Against Gun Violence, a group funded by New York Mayor Michael Bloomberg that has been working with some of the victims' families. Some of those families have been trying for months to persuade lawmakers to back tighter gun control measures, including background checks.
VICE PRESIDENT JOE BIDEN: The amendment is not agreed to.
MARGARET WARNER: But that legislation failed to pass the Senate in April. Now some senators, including some who voted no, are said to be discussing an amended bill.
Families came to Capitol Hill yesterday vowing to support it.
JILLIAN SOTO, Sister of Newtown Victim: We will continue to fight until Congress stands up and does something to make us safer from gun violence.
MARGARET WARNER: Senate Majority Leader Harry Reid endorsed the effort, but had a warning.
SEN. HARRY REID, D-Nev.: The writing is on the wall. Background checks will pass the United States Senate. It's only a question of when. I want to be very, very clear, though. In order to be effective, the bill that passes the Senate must include background checks, and not a watered-down version of background checks.
MARGARET WARNER: Gun control advocates have had mixed success at the state level. Several states, including Colorado, Maryland and New York, have passed tighter restrictions. But other states, like Arkansas and Mississippi, have eased them.
Just yesterday, Nevada Gov. Brian Sandoval, a Republican, vetoed a bill mandating background checks for all purchases in his state.
SEN. JOE MANCHIN, D-W.Va.: I'm Joe Manchin.
MARGARET WARNER: The National Rifle Association is fighting back as well.
JOE MANCHIN: As your senator, I will protect our Second Amendment rights.
NARRATOR: That was Joe Manchin's commitment.
MARGARET WARNER: It plans to spend $100,000 dollars running this ad in West Virginia, asking voters to remind Democratic Sen. Joe Manchin, who co-sponsored bipartisan Senate legislation, to support gun rights.
The White House also may be making a new push of its own. Vice President Joe Biden will be hosting a gun control event on Tuesday.