CHICAGO (AP) — New research shows active shooters with semi-automatic rifles wound and kill twice as many people as those using non-automatic weapons.

But the analysis shows that regardless of the weapon used, chances of dying, if hit, are the same.

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Researchers say that’s because these attacks tend to occur in relatively confined spaces, with shooters whose only intent is to kill.

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

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Roughly four people on average were killed in semi-automatic attacks, versus about two in other attacks.

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

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