A government-funded research project released on Friday sheds new light on the upward trend of mass shootings in the US, finding that the number of Americans dying from mass shooters is on the rise, and most people who commit such acts of violence have a history of trauma or were in a state of crisis.

The Violence Project, funded by the justice department’s National Institute of Justice, examined 172 mass shootings — defined as killing four or more people — dating back more than 50 years.

It found that of all the mass shootings that took place between 1966 and 2019, more than half took place since 2000, with 20 per cent of them occurring between 2010 and 2019. In the last five years of the study period, an average of 51 people died from mass shootings per year, compared with only eight people in the 1970s.

The justice department unveiled some of the study’s highlights the day after President Joe Biden and attorney- general Merrick Garland met New York City’s mayor to call for greater investments in local police. “This study reveals a deeply unsettling trend: more Americans are dying at the hands of mass shooters.”