How rare are female school shooters?

It is rare for school shooters to be female, according to the data and experts who study such events.
In fact, the percentage of people who have perpetrated mass shootings who are female is in the low single digits, according to various organizations that study such incidents.
Of 544 school shooting incidents over an 11-year period, less than 5% of the shooters were female, according to Everytown for Gun Safety, a nonprofit group that advocates for stronger gun laws. The group noted that the gender of the shooter is not always available so data are incomplete.
“Statistically, it is very rare that a school shooter is female,” said John Feinblatt, president of Everytown for Gun Safety. “Nonetheless, we can’t lose sight of what really matters: No child should be dodging bullets while at school and no teenager should be able to get their hands on a gun.”
Shock reverberated across Wisconsin Monday as law enforcement identified 15-year-old Natalie Rupnow, who went by Samantha, as the suspected shooter who killed a student and teacher at Abundant Life Christian School in Madison.
Justin Heinze, an associate professor of health behavior and health equity at the University of Michigan, said while school shootings are extremely distressing, they are comparatively rare compared to other firearms deaths and therefore drawing data from such incidents warrants caution.
“We're talking about an outlier of an outlier,” he said, referring to female school shooters. “But I'll tell anybody who asks me that there is not necessarily a profile. I cannot give you individual characteristics, or some patterns of behavior, or some life experiences that produce with any real accuracy, who might end up perpetrating an event like this."
"I think we need to be careful when we have conversations like this, because then you can kind of conflate pieces of information," he added.
In general, school shooters tend to most often be white males who target suburban and or rural schools, the data shows.
Heinze said there is survey data showing that among students who say they have brought a gun to school, the ratio is more even between males and females. However, it is not clear from those surveys why the students were bringing firearms to a school campus.
Studies on effectiveness of security measures to prevent school shootings are lacking
Heinze also said there isn't good data on the effectiveness of security precautions that schools are putting in place to prevent such shootings. Part of the challenge is measuring something that didn’t happen, and then figuring out why it didn’t happen.
In researching school shootings, there are almost always indicators before the shootings, Heinze said, adding he was speaking of cases in general and not the Abundant Life Christian School case. And it is important that such signs be reported to schools and law enforcement.
“We'll often say that by the time someone has brought a gun to school, it's too late. We might be able to mitigate that harm. We might be able to stop a shooting, but really we want to be emphasizing efforts that are well prior to an event,” he said.
“Often at least one person and sometimes more than two or three either saw something online, noticed something in the classroom, whichever it might be," he added.
Heinze said in the aftermath of the shooting, there may be trauma responses not just in Madison and Wisconsin but nationwide.
“It can make it very difficult for students to go to school, and everybody manifests these concerns of trauma in different ways,” he said. “So it's trying to remind folks to be on the lookout for those that might be experiencing stress related to this incident."