Weak state gun laws that allow for some criminals to possess firearms legally is contributing to the high rate of gun violence in the country, according to a new report by researchers at the Johns Hopkins Bloomberg School of Public Health.

"Mass shootings bring public attention to the exceptionally high rate of gun violence in the U.S., but policy discussions rarely focus on preventing the daily gun violence that results in an average of 30 lives lost every day," said Daniel Webster, ScD, MPH, director of the Johns Hopkins Center for Gun Policy and Research and lead author of the report. "Addressing weaknesses in existing gun laws by expanding prohibitions for criminals, perpetrators of domestic violence, youth, and drug abusers, and closing the loopholes that allow prohibited persons to obtain guns can be effective strategies to reduce gun violence. It is important to note that making these changes to our gun laws would not disarm law-abiding adults."

Federal law prohibits felons and perpetrators of domestic violence, among others, from possessing firearms legally. However, in the 13 states that have gun laws that are no more strict than federal law, people who have been convicted of misdemeanor crimes and those convicted of felony crimes in juvenile court are still allowed to own firearms -- even if those crimes were violent or involved firearms.

A study published earlier this year found that 29 percent of individuals incarcerated for gun crimes in these 13 states had criminal records or would have been too young to legally possess a firearm in states with the strictest standards for gun ownership. Research has found those charged with a misdemeanor crime who were legally able to buy handguns "committed crimes involving violence following those purchases at a rate two to ten times higher than that of handgun purchasers with no prior convictions."

In addition, among those incarcerated for gun crimes who were legally prohibited from possessing a firearm, almost all acquired their gun from a supplier that was not required to do a criminal background check.

Federal law has required prospective gun owners to pass a background check since 1994, when the Brady Act took effect. But many criminals are able to obtain guns through the so-called private sales loophole, according to the report. Unlike licensed gun suppliers, private sellers at gun shows and other venues are not required to conduct a background check.

"Many people don't realize that, in most states, individuals convicted of violent misdemeanors with court-issued restraining orders for domestic violence or who have a serious history of mental illness or substance abuse, can legally possess firearms," Webster said. "Federal gun laws allow private gun sellers to sell their guns with no questions asked of purchasers or proof that the purchaser has passed a criminal background check. Survey research shows that 82 percent of gun owners want that loophole fixed."

Though lax state laws regarding who can legally possess firearms has helped drive up violence, gun retailers that ignore federal law are one of the "most important channels for diverting guns to traffickers and criminals," according to the report. Not surprisingly, criminals are much less likely to illegally acquire firearms in states that license retail gun sellers, require careful record keeping, and conduct regular compliance inspections.

"Unfortunately, Congress has repeatedly weakened regulation, oversight, and accountability of federally licensed gun dealers," the report noted. "The Firearm Owners Protection Act of 1986 reduced penalties for gun sales law violations, increased standards of evidence for successful prosecution of gun sellers, and limited the Bureau of Alcohol, Tobacco and Firearms (ATF) compliance inspections."

The U.S. firearm homicide rates are 22 times higher than the average of all other high-income countries. Guns were used to kill more than 31,000 people in the United States in 2010.

"The toll is unprecedented among high-income nations," the report concluded. "Weaknesses in current gun laws contribute to this burden by establishing low standards for legal gun ownership and significant loopholes in policies designed to keep guns from prohibited persons. When states expand firearm prohibitions to high-risk groups, and adopt comprehensive measures to prevent diversion of guns to prohibited persons, fewer guns are diverted to criminals, and there is less violence."