Let’s clarify the statistics on this. The percentages used here are primarily from Mother Jones that has been maintaining a database of “mass shootings” since the Aurora, Colorado shooting. In short white males do this stuff primarily. There are issues with defining mass shootings and there have been criticisms of Mother Jones’ data but for being under reported.
Do not get bogged down in details. White males are the most likely cause of mass murders in the US. That needs to be dealt with. Here is the result of Politifact looking at the Mother Jones’ data: