A new study has found that around 60 more people have been murdered each year since the state of Missouri made it easier to buy a handguns without going through a background check.

In the study which will be published in an issue of the Journal of Urban Health, a team of researchers led by Johns Hopkins Center for Gun Policy and Research Director Daniel Webster found that between 55 to 63 more people were murdered each year after Missouri repealed its permit-to-purchase (PTP) handgun law in 2007.

“This study provides compelling confirmation that weaknesses in firearm laws lead to deaths from gun violence,” Webster said in a press release. “There is strong evidence to support the idea that the repeal of Missouri’s handgun purchaser licensing law contributed to dozens of additional murders in Missouri each year since the law was changed.”

After the law was repealed, unlicensed sellers were no longer required to perform background checks before selling their guns.

While murders in Missouri spiked between 2007 and 2012, bordering states experienced no significant increases. And the overall murder rate in the U.S. declined by 5 percent during that same period.

Researchers concluded that repealing the permit-to-purchase (PTP) law had given more murderers access to guns.

“Because many perpetrators of homicide have backgrounds that would prohibit them from possessing firearms under federal law, they seek out private dealers to acquire their weapons,” Johns Hopkins Center for Gun Policy and Research Deputy Director Jon Vernick explained. “Requiring a background check on all gun sales is a commonsense approach to reducing gun violence that does not infringe upon the Second Amendment rights of law-abiding gun owners.”

The study is being presented at the American Association for the Advancement of Science this month.