Trump claiming about the killer's father in the background.....saying 'They knew....they knew'.

I mean...what the entire fuck? Just goes to show how stupid Trump supporters are. What does it mean to say Hillary's people 'knew' that a mass killer's father was in the seats? And what possible motive would they have in doing that? 'Hey guys...we should sneak the club shooter's father into the background of her speech'. Exactly how low is this lowest common denominator that he's going after? 'Hillary KNEW that the murderer's father was there!' I can't get over it lol....what does that mean?

'They knew....they knew'. So the contention is that they're lying about it? Why in the world would they do that? Goddamn this is so ridiculous.