News Release

Repeal of Missouri's background check law associated with increase in state's murders

Peer-Reviewed Publication

Johns Hopkins Bloomberg School of Public Health

SPECIAL NOTE: This news release, made public on EurekAlert! on 15 February 2014, was updated by the source on 24 April 2014. The Journal of Urban Health has accepted for publication an Erratum to: “Effects of the Repeal of Missouri’s Handgun Purchaser Licensing Law on Homicides” by Daniel W. Webster, Cassandra Kercher Crifasi, and Jon S. Vernick. The Erratum concerns estimates generated from regression analyses due to errors identified in the data for certain covariates used in those analyses. The corrected data are very similar to, but are more accurate than, the findings previously published. As a result of the errors, three corrections have been made to the news release:

  1. Missouri’s 2007 repeal of its permit-to-purchase (PTP) handgun law contributed to a fourteen percent increase in Missouri’s murder rate through 2012 (updated from sixteen percent; first paragraph of press release).
  2. The law’s repeal was associated with an additional 49 to 68 murders per year in Missouri between 2008 and 2012 (updated from 55 to 63 additional murders per year; second paragraph of press release).
  3. The repeal of Missouri’s PTP law was associated with a twenty-five percent increase in firearm homicides rates. (updated from twenty-three percent; sixth paragraph of press release).

CORRECTED NEWS RELEASE: Missouri's 2007 repeal of its permit-to-purchase (PTP) handgun law, which required all handgun purchasers to obtain a license verifying that they have passed a background check, contributed to a fourteen percent increase in Missouri's murder rate, according to a new study from researchers with the Johns Hopkins Center for Gun Policy and Research.

The study, to be published in a forthcoming issue of Journal of Urban Health, finds that the law's repeal was associated with additional 49 to 68 murders per year in Missouri between 2008 and 2012. State-level murder data for the time period 1999-2012 were collected and analyzed from the Federal Bureau of Investigation's (FBI) Uniform Crime Reporting (UCR) system. The analyses controlled for changes in policing, incarceration, burglaries, unemployment, poverty, and other state laws adopted during the study period that could affect violent crime.

The increase in murders with firearms in Missouri began in the first full year after the PTP handgun law was repealed when data from crime gun traces revealed simultaneous large increases in the number of guns diverted to criminals and in guns purchased in Missouri that were subsequently recovered by police in border states that retained their PTP laws.

"This study provides compelling confirmation that weaknesses in firearm laws lead to deaths from gun violence," said Daniel Webster, ScD, MPH, director of the Johns Hopkins Center for Gun Policy and Research and the study's lead author. "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."

Webster and colleagues found that the spike in murders in Missouri following the PTP law repeal only occurred for murders in Missouri committed with a firearm and was widespread across the state's counties. Following the change in Missouri's gun laws, none of the states bordering Missouri experienced significant increases in murder rates and the U.S. murder rate actually declined by over five percent. The researchers also analyzed annual data from death certificates through 2010 compiled by the Centers for Disease Control and Prevention, and determined that the repeal of Missouri's PTP law was associated with a twenty-five percent increase in firearm homicides rates.

For firearm sales by federally licensed firearm dealers, federal law requires prospective purchasers to pass a criminal background check and sellers to maintain records of the sale. But federal law and laws in most states exempt these regulations when the firearm seller is unlicensed. The researchers suggest that universal background checks and firearm purchaser licensing affect homicide rates by reducing the availability of guns to criminals and other prohibited groups.

"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," said study author Jon Vernick, JD, MPH, deputy director for the Johns Hopkins Center for Gun Policy and Research. "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."

Only fifteen states require individuals purchasing handguns from unlicensed sellers to pass background checks, with ten of these states requiring all purchasers to acquire a permit-to-purchase license. A 2013 public opinion survey from Johns Hopkins found the majority of Americans (89 percent) and gun owners (84 percent) support requiring a background check system for all gun sales. The majority of Americans (77 percent) and gun owners (59 percent) also reported supporting requiring people to obtain a license from a local law-enforcement agency before buying a gun to verify their identity and ensure that they are not legally prohibited from having a gun.

Webster is presenting these data at the annual meeting of the American Association for the Advancement of Science, February 13th-17th in Chicago. He will also discuss the study during a conference press briefing on Saturday, 11:00 a.m CST, Science-based Strategies for Reducing Gun Violence. The press briefing will be webcast live:


Cassandra Kercher Crifasi is also an author of "Effect of Missouri's Repeal of Its Handgun Purchaser Licensing Law on Homicides." The research was supported by the Joyce Foundation.

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