SAN FRANCISCO (KCBS)— U.S. Senator from California Dianne Feinstein opened a Senate judiciary committee hearing on Wednesday by playing a video that showed how a simple off-the-shelf device attached to a semi-automatic weapon can make it fire like a fully-automatic shotgun.

She called for a new assault weapons ban to reduce gun violence that has increased since the federal law expired in 2004. Her comments came during an often emotional committee hearing.

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“Since 1982 there have been at least 62 mass shootings across the United States,” Feinstein said.

Among the witnesses were Neil Heslin who recalled dropping off his six-year-old son at Sandy Hook Elementary in December.

“Jesse gave me a hug and a kiss at that time, said ‘Goodbye. I love you’ stopped, and said ‘I love mom too’. That was the last I saw Jesse,” said the grieving father.

At his side were photos: of his son as a baby, of them both taken on Father’s Day, six months before Jesse was among 20 first-graders and six administrators killed at Sandy Hook Elementary School in Newtown, Conn. That massacre has hoisted gun control to a primary political issue this year, though the outcome remains uncertain.

The hearing featured heated exchanges, such as when Graham pressed Milwaukee Police Chief Edward Flynn about the government’s prosecution of only a handful of the roughly 80,000 people annually who fail background checks after falsely stating they qualify for guns.

“I want to stop 76,000 people from buying guns illegally,” Walsh said, defending the background check system and heatedly interrupting Graham, a Senate rarity.

Former Rep. Sandy Adams, R-Fla., once a law enforcement officer, told the senators they have an opportunity to take effective action against gun violence. She has favored expanding the availability of mental health information to the authorities and opposes taking guns from people.

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“It is not time for feel-good legislation so you can say you did something,” she said.

That drew an angry objection from Sen. Richard Durbin, D-Ill., who said, “This is not feel-good legislation.”

Feinstein’s bill—and most of Obama’s guns agenda—will have to overcome opposition from the National Rifle Association, which has long kept lawmakers from enacting gun restrictions.

Another hurdle is uncertain support from moderate Democrats.

Feinstein’s measure has 21 co-sponsors, all Democrats. Including herself, it is sponsored by eight of the 10 Judiciary panel Democrats—precarious for a committee where Democrats outnumber Republicans 10-8. Among those who haven’t co-sponsored the measure is Chairman Patrick Leahy, D-Vt., who did not attend Wednesday’s session.

Her bill would ban future sales of assault weapons and magazines carrying more than 10 rounds of ammunition, exempting those that already exist. It specifically bans 157 firearms but excludes 2,258 others in an effort to avoid barring hunting and sporting weapons.

Meanwhile, the House Education and Workforce Committee debated ways to keep students safe, such as the NRA proposal for more armed guards at schools.

“Two thousand kids die each year in automobiles each year,” said Rep. Phil Roe, R-Tenn., comparing that number with the comparatively few children who die in schools. “Schools are safe places and for the most part they really are.”

Rep. George Miller, D-Calif., said school safety is linked to firearms, saying, “Turning schools into armed fortresses is not the answer.”

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