I think comrade is comparing the treatment of this shooter to a typical cis white male mass shooter. Since cis white male is the “default” it’s never brought up as an influence on their behavior and it’s not portrayed as representative of cis white males as a whole. If the person is part of a known minority group, however, their identity is used as a reason for what they did and suspicion is cast on the minority group as a whole, despite others in that group having nothing to do with whatever terrible act is being discussed. Hopefully that makes sense.