Alcohol is a major driver in American homicide. In about half of all U.S. homicides, either victim or perpetrator (or both) are under the influence at the time of the fatal act.

Taxing, regulating and restricting alcohol reduces its incidence in homicides, according to a new study in the Journal of Studies on Alcohol and Drugs.

The doctors from the Boston University School of Medicine and the Boston Medical Center further contend that decreasing the availability of alcohol could also decrease the homicide rate.

“Given the risks involved with alcohol use, strengthening effective alcohol policies could help prevent homicides,” said Timothy Naimi, the lead author and a physician at the BMC.

The homicide data came from victims killed between 2003 and 2012 in 17 states, as provided in the National Violent Death Reporting System.

The states were then evaluated by an alcohol policy scale measuring each state’s restrictiveness with the availability and use of the substance. The scale was determined by assessing 29 states.

(In the analysis, Utah and Oklahoma had the most restrictive alcohol policies, while Maryland and Wisconsin had the least restrictive.)

Their overall findings: a 10 percent increase in the alcohol policy scale score was associated with an 11 percent decrease in the odds of any alcohol involvement of homicide victims, they conclude. 

Also among the findings: the restrictive alcohol policies were “protective” among at-risk groups including young adults, intimate partner violence-related killings and victims from firearms.

“More restrictive alcohol policy environments were associated with reduced odds of alcohol-involved homicide victimization overall and among groups at high risk of homicide,” they conclude. “Strengthening alcohol policies is a promising homicide prevention strategy.”

A similar meta-analysis of alcohol studies published last year by an Australian team found that decreasing liquor stores’ hours decreased rates of violence in several countries. The World Health Organization was advocating for a reduction in alcohol availability as early as 2009.

Similar population-level homicide studies have instead focused on the prevalence of guns. For instance, one nationwide statistical look in 2015 found that the states with the most guns were the ones with the highest rate of police officers killed in the line of duty.