This will likely fall on deaf ears, but:
A) Cops killing civilians will be judged differently from civilian shooter situations.
B) A shooter's ethnicity (and his/her targets) are important to understanding his/her motive.
If you cannot understand why the above statements are true, then you are being deliberately ignorant.
In my opinion every time someone commits a horrific act of violence the media immediately launches into full coverage on the killer and whatever demented reasoning brought them to murder. Bonus points for an utterly insane manifesto, which will be poured over for haunting excerpts.
Here's the thing though: every time we do that the next lunatic thinks (correctly) to himself "nobody ever seems to listen to my idiotic ramblings, but if I kill a few people, then people will listen". Now, that thought would never occur to you or I, because we aren't bat shoot crazy. However, if you were crazy, and you did have some sort of lunatic agenda you would look at the fame of the columbine killers, the boston bombers, the theater shooter, the church shooter (notice I'm not naming names) and so on and so forth. Everyone knows their names, the media has interviewed their families and co-workers and gone into endless details about what they think might have brought them to kill. We literally KNOW this most recent shooting was sparked by the media coverage of the church shooting.
There is no political motive that justifies killing the innocent, so we should not lend killers the platform. All murderers should be referred to as "murderous asshole" or something similar and there should be no media discussion of their motivations/manifestos/reasonings. Maybe, just maybe, if we stop glorifiying/publicizing this kind of idiocy it will plug the hole our failing mental health system is leaving open.
tl;dr The general public doesn't
NEED to understand a killers motive, it does more harm than good.