Why Are Still So Few People Considering That Trayvon Martin's Killer May've Been Mentally Ill?

I've said this before and again, but why is everyone still willing to give peeing-on-cars Jason Russell the psychosis pass all the way back to giving John Hinckley, Jr. a psychosis pass; but everybody calls George Zimmerman a racist murderer? Or was Jason Russell a famewhore? Was John Hinckley, Jr. just using Jodie Foster as an excuse because neither he nor she liked Republican actors from Hollywood? Even Geraldo Rivera forgot to consider that George Zimmerman could've had a manic or paranoic, or some other mental episode of some kind. Wait and see if George Zimmerman can and does plea not guilty by reason of insanity.