Don't try to convince people. Use the same method Q uses here… ask questions. Make them put 2 and 2 together that way it's them wanting more information, not you dumping more than they can handle.
Like for Parkland.. Ask why were the sheriffs told to stay outside? Why was the the school security video set 20 minutes behind? If you were running from a crime, would you go to walmart and then sit and eat at a McDonalds and then walk home?
Let them come to the realization that something isn't adding up. If they don't ask questions, wait for next news event and try again. If you try to make the connections for them, it's easier for them to call you crazy or dismiss it.