Why are female mass shooters so rare?

Nasim Aghdam's attack at YouTube HQ was a rare occurrence: only 4% of mass shooters in the US are female. source: https://ift.tt/2JktrJ5 #Headlines by: Original Post: https://ift.tt/2JktrJ5 https://ift.tt/2GYB2Pa
source: https://droolindognews.blogspot.com/2018/04/why-are-female-mass-shooters-so-rare.html