DENVER (KDVR) — Assault weapons are less common than other types of firearm in the kinds of mass public shootings of which Boulder’s grocery store massacre is an example. However, the incidents involving assault weapons have higher body counts.

Boulder shooting suspect Ahmad Alissa bought an AR-556 pistol on March 16. It is not yet confirmed that he used this weapon in the shooting, though reports mention both a rifle and handgun among the items police recovered at the scene.

As with mass shootings, there is no universally-accepted definition of “assault weapon.” Previous and current federal and state regulations generally involve some combination of functional and cosmetic factors such as semiautomatic firing capability, a detachable magazine with a 10-30 round capacity, a pistol grip and collapsible stock.

For analysis purposes, Data Desk considered an assault weapon to be a semiautomatic pistol, rifle, short barreled rifle or carbine with a pistol grip, collapsible stock and detachable magazine. It used a previously-considered definition of mass shooting involving a public place and at least four fatalities in a non-criminal context.

In 126 such shootings, handguns are more present, although nearly 40% of shootings involve more than one type of firearm.

Semiautomatic handguns are about twice as common as assault weapons in mass shootings, and handguns entirely about three times as common.

Only 15 shootings involved only an assault rifle. Three times as many involved only semiautomatic handguns.

Assault weapons were used in 28% of the 126 mass public shootings 1982-2021 with four or more fatalities. Semiautomatic handguns were used in 67% and revolvers in 18%. Combined, semiautomatic handguns and revolvers are present in 86% of mass public shootings.

Assault rifles are, however, correlated with higher victim counts. Tune into Data Desk tomorrow for a breakdown of total and average mass shooting victims according to respective weapons types.