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:
“There have been at least 184 mass public shootings in the U.S. since 1900, including the Las Vegas attack,” Duwe said. “Among these mass public shooters, non-Hispanic whites make up 63 percent, which is close to what we see for the U.S. population in general. So, the Mother Jones data actually underreport the extent to which whites are involved as mass public shooters.”