At one point, Sen. Lindsey Graham, R-S.C., used his questioning of Milwaukee Police Chief Edward Flynn to argue that the current background check system is not being well enforced, since only a handful of the roughly 80,000 people annually who fail those checks are prosecuted for filing documents saying they qualify to own the weapons.
Uncharacteristically for a Senate hearing, Flynn interrupted the senator, saying, "I want to stop 76,000 people from buying guns illegally," a reference to the gun purchases that the background check system blocked last year. "That's what background check does."
His remark drew applause from spectators in the room.
Across the Capitol, the House Education and Workforce Committee planned to hear from school safety experts and counselors about how to keep students safe.
"How can we be confident that something like this does not happen again?" asked John Kline, R-Minn., the Republican panel's chairman as the meeting began.
His Democratic counterpart, Rep. George Miller of California, said school safety is linked to firearms.
"Sandy Hook is an event that calls us on us as policymakers to do something. .<!p>.<!p>. A school must be a place where children feel secure," Miller said. "Turning schools into armed fortresses is not the answer."
Instead, he said schools need to add counseling services and mental health programs.
In their prepared testimony, witnesses there were careful not to endorse the NRA's suggestion that armed volunteers in schools were a realistic answer to prevent future attacks.
"I cannot emphasize enough how critical it is for officers to be properly selected and properly trained to function in the school environment," said Mo Canady, executive director of the National Association of School Resource Officers.
Despite the raw emotion, Feinstein's effort to ban assault weapons is expected to fall short due to opposition by the National Rifle Association and many Republicans, plus wariness by moderate Democrats.
Feinstein's bill has attracted 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. Democrats on the panel who haven't co-sponsored the measure include the chairman, Pat Leahy of Vermont, who said Monday he hadn't seen the bill.
Obama made bans on assault weapons and large capacity magazines key parts of the gun curbs he proposed in January in response to the Connecticut school massacre.
The cornerstone of his package is a call for universal background checks for gun buyers, some version of which seems to have a stronger chance of moving through Congress. Currently, only sales by federally licensed gun dealers require such checks, which are designed to prevent criminals and others from obtaining firearms.
Feinstein's bill would ban future sales of assault weapons and magazines carrying more than 10 rounds of ammunition but exempt those that already exist. It would bar sales, manufacturing and imports of semiautomatic rifles and pistols that can use detachable magazines and have threaded barrels or other military features. The measure specifically bans 157 firearms but excludes 2,258 others in an effort to avoid barring hunting and sporting weapons.
Feinstein, who helped create a 1994 assault weapons ban that expired in 2004, and other supporters cite studies showing use of the firearms in crimes diminished while the prohibition lasted. A 2004 report said the proportion of gun crimes involving assault weapons dropped by up to 72 percent in five cities studied.Opponents cite data from that same study showing assault weapons were used in only 2 percent to 8 percent of gun crimes, arguing that a ban would have little impact. The study also estimated there were 1.5 million assault weapons owned privately in the U.S. in 1994, and an estimated 30 million high-capacity magazines as of 1999, which critics say means exempting them would diminish a ban's effect.