Meanwhile, President Barack Obama on Wednesday unveiled a package of gun control proposals including closing background check loopholes, banning "military style" assault weapons, and limiting magazines to 10 bullets, as well as signing 23 executive orders.
Experts said a ban on assault weapons will have a tough time passing in a bitterly divided Congress, and gun proponents point out that the second amendment of the U.S. Constitution protects their right to bear arms.
The amendment, however, is not absolute, and courts and past presidents, including Republican President George Bush Sr., were in favor of some gun control legislation.
Adam Winkler, constitutional law expert at University of California, Los Angeles, said most of the measures under consideration in Washington are legal under the U.S. Constitution, including a ban on assault weapons, although that opinion is not unanimous among experts.
Legality rests on whether a weapon is in common use, or whether it is unusual, he said Tuesday at a summit on gun violence at Johns Hopkins University.
Still, some criminologists argue a ban on assault weapons will not stop a determined mass murderer, who will use a pistol, a bomb or a knife if he has no access to assault weapons, although others say some laws could at least reduce the carnage.
While many Americans favor the type of beefed up background checks the president proposed, there may be limits on effectiveness, as criminals usually do not get their guns from licensed dealers, said Philip J. Cook, professor at Duke University, on Monday at the same summit. Instead, they obtain them from markets that do not require background checks, he said.
Dover echoed that sentiment, saying that criminals are not likely to purchase firearms at his store, adding that he has turned away customers who had odd demeanors or seemed to be in a rush.
A Gallup poll released Monday found Americans' dissatisfaction with current gun laws spiked by 25 percent from the same period a year ago, although 43 percent remain satisfied with current laws.
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