Changes in state policies impact fatal, non-fatal assaults of law enforcement officers

The researchers looked at the relationship between assault data involving law enforcement officers and changes in three policies at the state level: three-strikes laws, which impose mandatory decades-long sentences when a criminal is convicted of a third crime; right-to-carry or concealed-carry laws, which reduce restrictions for individuals to carry concealed firearms in public; and permit-to-purchase measures, which require prospective handgun purchasers to obtain a permit or license after passing a background check.

"Policy can influence the ways in which criminals and the public interact with law enforcement," says study leader Cassandra Crifasi, PhD, MPH, an assistant scientist with the Johns Hopkins Center for Gun Policy and Research. "Laws governing penalties for repeat offenders and the purchase and carrying of handguns could influence the safety of law enforcement officers."

The authors found that three-strikes laws were associated with a 33 percent increase in the risk of fatal assaults of law enforcement officers and a 62 percent increase in fatal non-handgun assaults. Non-handgun assaults include assaults with rifles and shotguns as well as other weapons such as knives. The association between the laws and fatal assaults committed with a handgun was weak, which the researchers posit is not surprising, as three-strike laws do not inherently impact the availability of any one type of weapon used in assaults. The study compared the 24 states that had changes in their three-strikes laws between 1984 and 2013 to the remaining 26 states.

"In the case of three-strikes laws, it appears that chronic offenders may be killing officers to evade capture and possible life imprisonment," Crifasi says.

Previous research has examined the link between right-to-carry or concealed-carry gun laws on fatal assaults in the general population. The Bloomberg School study is believed to be the first to examine the effects of these laws on both fatal and non-fatal assaults of law enforcement officers and found no associations between the laws and either type of assault against officers. The researchers compared assault data involving law enforcement officers in the 17 states that made changes to their right-to-carry laws between 1984 and 2013 to the 33 states that made no changes.

Study author Daniel Webster, ScD, MPH, director of the Johns Hopkins Center for Gun Policy and Research, offers one explanation for the lack of association between right-to-carry and assaults against officers: "Many of those most likely to commit firearm violence are prohibited from possessing firearms and therefore unable to obtain a permit to carry a concealed handgun."

In 2014 and 2015, Webster and colleagues documented the impact on firearm homicides and suicides in Missouri and Connecticut after both states made changes to their handgun permit-to-purchase laws that require all individuals to obtain a permit or license to purchase a handgun after passing a background check.

The new study, believed to be the first to examine the impact of changes in permit-to-purchase handgun laws on assaults on law enforcement officers, finds that these laws appear to protect law enforcement officers against handgun assaults.

Specifically, Missouri's repeal of its handgun permit-to-purchase law was associated with a twofold increase in the risk of non-fatal handgun assaults on law enforcement officers and no corresponding change in non-fatal, non-handgun assaults. The number of officers who died in Missouri is too small to make any conclusions about fatal assaults.

Connecticut's handgun permit-to-purchase law was associated with a 80 percent decrease in fatal assaults of law enforcement officers with handguns. This association was also not statistically significant due to the rarity of these deaths.

"Prior research has shown that laws requiring handgun purchasers to obtain permits from law enforcement agencies following background checks are associated with fewer guns diverted to criminals and lower firearm homicide rates, says Webster. "The prior research findings coupled with the fact that changes in permit-to-purchase handgun laws were linked with changes in the risk of handgun assaults on officers suggest the laws protect law enforcement officers as well as ordinary citizens."

Although the rates of fatal assaults on law enforcement officers have declined over the past several decades, their homicide rates are consistently higher than that of the general population and higher compared with other public service occupations. Most of the fatal assaults against law enforcement officers are committed by firearm.