Objective To evaluate the impact of state-level policy changes on assaults on law enforcement officers (LEOs) in the USA.
Methods Pooled time series and cross-sections with negative binomial regression were used to estimate the impact of state-level changes of right-to-carry (RTC), three-strikes and permit-to-purchase (PTP) handgun laws on fatal and non-fatal assaults of LEOs. LEO assaults were stratified by weapon type (all methods, handgun and non-handgun) and whether or not the assault was fatal. Data were collected from the Federal Bureau of Investigation's Law Enforcement Officers Killed and Assaulted database and analysed for the period 1984–2013 for fatal assaults and 1998–2013 for non-fatal assaults.
Results RTC laws showed no association with fatal (p>0.4) or non-fatal (p>0.15) assaults on LEOs. Three-strikes laws were associated with a 33% increase in the risk of fatal assaults on LEOs. Connecticut's PTP law was not associated with fatal (p>0.16) or non-fatal (p>0.13) assaults. Missouri's repeal of its PTP legislation was marginally associated with a twofold increased risk of non-fatal handgun assaults (p=0.089).
Conclusions This research indicates that three-strikes laws increase the risk of fatal assaults. RTC laws are not associated with increased risk of assault. Missouri's PTP repeal may increase the risk of non-fatal handgun assaults.