An acceleration of mass shootings. More public mass killings. More than 200 people across the nation shot on the Fourth of July.

The United States frequently reaches horrific new highs of the gun violence epidemic. The latest way: A deadly six months in what figures to be the most mass killings in a year.

There have been 30 mass killings in 2023 — more at this point in the year than any other since at least 2006, according to the USA TODAY/Northeastern University/Associated Press Mass Killings Database. A mass killing is defined as four or more people killed, not including the perpetrator. Of those 30 mass killings, 29 involved a gun.

The incidents this year have left nearly 150 people dead and more than 70 injured. But that’s only the tip of the iceberg.

“The bad year continues,” said James Alan Fox, a professor at Northeastern University who has studied mass killings for 40 years. “If the second half of the year is anything like the first half, this will be a high watermark.”

Here’s what to know about mass killings and shootings in the United States in 2023.

How many mass killings in 2023?

The United States typically witnesses dozens of mass killings a year. The incidents are typically shootings and often taken place in private spaces, such as inside homes.