April 4, 2018 9:06 AM EDT

When an active shooter was reported at YouTube’s San Bruno, Calif., headquarters on Tuesday, it became the latest in a string of chilling incidents that have begun to feel all too familiar.

But the YouTube incident had one major difference from other recent tragedies: It involved a female suspected shooter, 39-year-old San Diego resident Nasim Aghdam. Aghdam was found dead at the scene from an apparent self-inflicted gunshot wound. Though law enforcement officials have not identified a possible motive in the YouTube shooting, Aghdam was a prolific YouTube user — and a vocal critic of the site, which she claimed “discriminated and filtered” her videos to reduce their viewership.

While there’s no such thing as a profile of a mass shooter, female perpetrators are exceedingly rare, according to a 2014 study by the FBI. The study, which examined 160 active shooter incidents that occurred in the U.S. between 2000 and 2013, found that just 3.8% of these attacks — six in total — involved a female shooter. An additional three incidents involving female shooters occurred between 2014 and 2016, according to FBI records.

The most recent mass shooting involving a woman, according to the Washington Post, was the deadly 2015 attack on an office party in San Bernardino, Calif., which left 14 people dead.

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Write to Jamie Ducharme at jamie.ducharme@time.com.

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