—Product features: Which firearms are most dangerous and why. Manufacturers could be pressured to fix design defects that let guns go off accidentally, and to add technology that allows only the owner of the gun to fire it (many police officers and others are shot with their own weapons). Bans on assault weapons and multiple magazines that allow rapid and repeat firing are other possible steps.
—"Environmental" risk factors: What conditions allow or contribute to shootings. Gun shops must do background checks and refuse to sell firearms to people convicted of felonies or domestic violence misdemeanors, but those convicted of other violent misdemeanors can buy whatever they want. The rules also don't apply to private sales, which one study estimates as 40 percent of the market.
—Disease patterns, observing how a problem spreads. Gun ownership — a precursor to gun violence — can spread "much like an infectious disease circulates," said Daniel Webster, a health policy expert and co-director of the Johns Hopkins Center for Gun Policy and Research in Baltimore.
"There's sort of a contagion phenomenon" after a shooting, where people feel they need to have a gun for protection or retaliation, he said.
That's already evident in the wake of the Colorado movie-theater shootings. Last week, reports popped up around the nation of people bringing guns to "Batman" movies. Some of them said they did so for protection.
Associated Press writer Pete Yost in Washington contributed to this report.
Violence prevention research: http://www.ucdmc.ucdavis.edu/vprp
CDC injury prevention: http://www.cdc.gov/violenceprevention/nvdrs/
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