And I think the mass killings af Americans by Americans with guns has gotten sideswiped in this thread by a focus on gender identity. Theres' another thread on this board for that topic.
Perhaps we can focus on the fact that typically consistent in a mass shooters history is trauma in their childhood - like sexual assaults, bullying, violence in the home and that the majority of them are committed by white, christian, male, loners, many of whom have targeted folks based on religion, race or where they are in proximity to a location that means something to the shooter. These men are looking for acceptance and approval, and have decided that this suicide, and taking others out with them is the way to gain that.
Of the 135 mass shootings in the US since 1985 only 4 were done by women. .03%
Most of these shooters got their guns "legally".
Most of the recent shootings have involved AR15 as the main weapon.
So the problem isn't gender identity. It's access to guns (mostly high velocity) and lack of stop gap measures to identify the folks that should have access to them. Most of whom are men.
https://www.npr.org/2021/03/27/981803154/why-nearly-all-mass-shooters-are-men