Since 2011, 10 or more victims in single mass shootings almost annually. A look at the numbers

Paste BN published a chart below of America’s largest mass killings in its print editions about six years ago after a gunman killed 70 concertgoers from his Las Vegas hotel room.

A trend had clearly taken root the chart shows.

In the six years following 2011, more than 10 people were killed in individual mass shootings in all but 2014. Two mass killings in 2012 claimed 38 lives between Sandy Hook Elementary School and a movie theater in Aurora, Colorado.

And so the chart continued to grow until the pandemic.

As we socially distanced for months, the country didn’t suffer a double-digit mass killing. Similarly, all mass deaths – four people or more, not including the killer – declined in 2020, according to the Paste BN, Northeastern University and The Associated Press database.

And then life returned to this new normal. We were reminded of it as we woke up Thursday morning: Someone had shot and killed 18 people in Lewiston, Maine, and left 13 injured.

Double-digit mass killings used to be less common

However you frame these killings of 10 or more people within the gun debate, they happened much less frequently before 2012. Even with five such incidents in five years during the 1980s, the U.S. averaged just one double-digit mass killing event about every four years.

Double-digit mass killings become more frequent

Four of the 10 largest mass killings have been at schools since the Virginia Tech shootings in 2007. But perhaps, it's the Sandy Hook killings that stand out on this chart. Since 2012, mass shootings claimed the lives of 10 or more people in every year but two, and most of those years had two or more.

Double-digit mass killings rise after the pandemic

Since 2017, the U.S. has averaged two double-digit mass killings every year – even including 2020 when none occurred. Lewiston was the second of 2023. In January, a shooter killed 11 and injured nine during a Chinese Lunar New Year celebration in Monterey Park, California.

Explore all the mass killings since 2006

A mass killing database created by Paste BN, Northeastern University and The Associated Press includes every mass killing since 2006 from all weapons in which four or more people, excluding the offender, were killed within a 24-hour time frame. The database also includes dozens of variables on each incident, offender, victim, and weapon.