Murder by Madman Enthusiastically Politicised

The lone witness to allege that the killer of British MP Jo Cox shouted "Britain First!" before and after the murder is himself a member of the rival British National Party.  Another witness, a Muslim, denies the statement was uttered.  Journalists, politicians, and the pundits of social media proceed with their confidently bigoted denunciation of anyone with any ideas in common with the crazy person.