Semiautomatics kill twice as many as other guns, study finds

CHICAGO — Active shooters with semiautomatic rifles wound and kill twice as many people as those using weapons that don’t self-load, although chances of dying if hit in either type of assault are the same, a new analysis shows.

Researchers examined FBI data on nearly 250 active shooter incidents in the country since 2000. Almost 900 people were wounded and 718 were killed.

One in 4 of these attacks involved semiautomatic rifles. These weapons automatically load each bullet after firing although firing requires pulling the trigger for each round.

Recent attacks involving semiautomatic weapons include Sandy Hook Elementary School in Newtown, Conn., and the Florida shootings at Pulse nightclub in Orlando and Parkland High School in Parkland, near Coral Springs.

Semiautomatics, which include some assault weapons, often are thought of as being more lethal. Since they can fire rapidly, chances of being hit in those circumstances are high, the study shows.

But in active shooter attacks, which tend to occur in confined spaces and with an intent to kill, the results suggest all types of guns can be equally deadly, said lead researcher Dr. Adil Haider, a trauma surgeon at Brigham and Women’s Hospital in Boston.

Overall, 44 percent of people hit in active shooter attacks involving semiautomatic weapons died, the same as those wounded in attacks not involving semiautomatic rifles, showing that “the death rate if you got hit by a bullet was the same,” Haider said.

“Active shooters are hellbent on killing people,” he said. “The big difference — and this is not such a big surprise — is if you give them a semiautomatic, they’re able to shoot twice the number of people.”

The average number of people wounded in semiautomatic attacks totaled nearly six, versus about three in attacks with other weapons. Roughly four people were killed on average in semiautomatic attacks, compared with about two in other attacks, the study found.

The study’s results were published Tuesday in the Journal of the American Medical Association.

Haider said the study highlights a need to better track details on types of weapons used in active shooter attacks; FBI figures do not detail whether weapons used were semiautomatic so the researchers got that information from court and police documents and news media reports.

Semiautomatic rifles cause more deaths and injuries, but “firearms in general, regardless of the type, are extraordinarily lethal weapons,” said Dr. Cassandra Crifasi, deputy director of the Johns Hopkins Center for Gun Policy and Research, who was not involved in the research.