No trick. Simple statistics - just like you post about African Americans.<quoted text>Cute trick, but I've seen it before.
Yes, if white Americans are roughly 70% of the population you need to divide that number in half to estimate the overall % that white men equal relative to the whole of the population. Where this falls apart though, is that school shooters are overwhelmingly male. The result is that you divide all the genersl population numbers by two anyway. It cancels out.
Dan the Man continues with his lies and tricks.
Accept mine or retract yours. Your choice.