Data compiled by The Associated Press, USA Today and Northeastern University shows that there were more mass killings in 2019 than any year dating back to at least the 1970s.

In all, there were 41 mass killings, defined as when four or more people are killed excluding the perpetrator. Of those, 33 were mass shootings. More than 210 people were killed.

According to the data,

• The 41 mass killings were the most in a single year since the AP/USA Today and Northeastern database began tracking such events back to 2006, but other research going back to the 1970s shows no other year with as many mass slayings. The second-most killings in a year prior to 2019 was 38 in 2006.
• The 211 people killed in this year's cases is still eclipsed by the 224 victims in 2017, when the deadliest mass shooting in modern U.S. history took place in Las Vegas.
• California, with some of the most strict gun laws in the country, had the most, with eight such mass slayings. But nearly half of U.S. states experienced a mass slaying, from big cities like New York, to tiny towns like Elkmont, Alabama, with a population of just under 475 people.
• Firearms were the weapon in all but eight of the mass killings. Other weapons included knives, axes and at least twice when the perpetrator set a mobile home on fire, killing those inside.
• Nine mass shootings occurred in a public place. Other mass killings occurred in homes, in the workplace or at a bar.

James Alan Fox, is a criminologist at Northeastern University and one of the nation’s leading researchers on mass murder, says “There’s a lot of misinformation floating around when it comes to mass murder. My hope is that this database will be a standard place where people can get the most valid information.”