How the data were gathered
It wasn’t easy assembling the data for this report.
No one agency or office compiles a comprehensive list of instances when police use deadly force, so CommonWealth gathered the information from the state’s district attorneys, the State Police, state and federal court records, and the state Department of Public Health, which tracks all shooting injuries and deaths that involve some sort of treatment at a hospital or clinic.
Each source had deficiencies in its data. District attorneys from at least four counties, for example, failed to list at least one case their offices had handled. The State Police data, covering all of the state except Boston, Worcester, and Springfield, where local police handle investigations, failed to include 11 fatal shootings in Plymouth, Bristol, and Norfolk counties. The State Police list, however, included three shootings by state troopers that were not identified by district attorneys.
Boston police, who were involved in 16 shooting deaths since 2002, the most in the state, initially promised to provide information on their cases but never did despite numerous follow-up calls and emails. Officials in the Worcester and Springfield police departments did not return calls or respond to requests for information.
It’s also tough to put the Massachusetts incidents of police deadly force in context with the rest of the country. Nationally, the FBI gathers data on deadly force incidents involving police, but the information is woefully incomplete because it is only collected from jurisdictions that report statistics to the agency. In 2012, the FBI data indicate there were a total of 410 justifiable homicides nationally by law enforcement officers, defined as the killing of a felon by an officer in the line of duty. The FBI data offer a state-by-state breakdown only for a category that lumps together justified homicides by both law enforcement officials and private citizens. For Massachusetts, that number was two in 2012, well below the eight we uncovered involving just police.