JEFFERSON CITY - A Johns Hopkins University study found that the murder rate in Missouri increased after the repeal of permit-to-purchase in 2007.

The study will be published in an upcoming issue of the Journal of Urban Health.  The study found that the increase in murder with firearms in Missouri started after 2007.   The study assoicated an additonal 55 to 63 murders per year between 2008 and 2012.

Missouri's leading 2nd Amendment rights advocate Sen. Brian Nieves, R-Washington, questions the accuracy of the study's findings.

"This is something that would require a heck of a lot more scrutiny, not only from myself, but anybody else that wants to either believe or refute this," Nieves said.

"At this point, I don't know the validity of this, I don't know its background, I'm not familiar with any of the names, so I probably don't have a real strong opinion about it, one way or another," Nieves said.

 The 2007 law that repealed permit-to-purchase also made the "castle doctorine" enforceable in Missouri.  Not to be confused with "stand your ground," the castle doctorine allows citizens to defend themselves, with deadly force, in their homes.