By Linda Carroll

(Reuters Health) – Shooters carrying semiautomatic rifles have the ability to kill and injure more people than those armed with handguns, shotguns and non-semiautomatic rifles, a new study shows.

Researchers poring over FBI data found that shooters could hit nearly twice as many people if they were armed with a semi-automatic rifle, according to the study published in JAMA.

Bullets from both types of guns “kill at the same rate,” said study coauthor Dr. Adil Haider, a trauma surgeon and director for the Center for Surgery and Public Health at Brigham and Women’s Hospital and Harvard Medical School. “But the big difference is that if an active shooter uses a semiautomatic weapon, he’s able to hit twice as many people.”

The FBI defines an “active shooter incident” as a situation in which an individual is actively engaged in killing or attempting to kill people in a confined or populated area, Haider said. The agency has tracked all active shooter incidents since 2000, though it does not note in its records whether the weapon used was semiautomatic.

Haider and his colleagues extracted a plethora of incident details from the FBI’s database, including shooter age and name, year, location, number of people wounded or killed, type of place the shooting occurred–for example, school, government office, house of worship – and the kind of firearms found at the site.

To get information on whether the weapons used were semiautomatic, the researchers scoured court records and media reports for each incident.

Haider and his colleagues opted to leave out major two incidents: the Las Vegas shooting, because the semiautomatic rifles had been converted to automatic with bump-stocks, and the San Bernardino shooting, because more than one shooter was present.

Out of the 248 active shooter incidents, 61 involved a semiautomatic rifle, while 187 involved handguns (154), shotguns (38) and non-semiautomatic rifles (15). Shooters wounded 898 people and killed 718.

Although people were just as likely to die after being struck by a bullet, no matter what type of weapon was used, far more were hit when a shooter used a semiautomatic rifle.

“This study contributes toward the debate on whether we should reenact the Federal Assault Weapons Ban of 1994,” Haider said. “Now we have some data to prove that active shooters can be twice as harmful if they use a semiautomatic rifle.”

Among the guns deemed to be assault weapons in the 1994 ban was the currently popular AR-15. Those guns became available again when the ban expired 10 years after it became law.

The new findings weren’t surprising to Daniel Webster, director of the Center for Gun Policy and Research at the Johns Hopkins Bloomberg School of Public Health. Webster was not involved in the new research.

“The study is consistent with one might expect,” Webster said in an email. “Semiautomatic rifles, especially the type used in mass shootings, tend to be equipped with large capacity ammunition feeding devices that allow shooters to fire more bullets uninterrupted within a very short period of time and allow for rapid reloading.”

SOURCE: Journal of the American Medical Association, online September 11, 2018.