Knowing The Warning Signs of Dangerous Behavior
![](https://media.wnyc.org/i/800/0/c/85/1/27049892463_0f756dcf4c_o_DvMVJp0.jpg)
Activist with placard at London's vigil in memory of the victims of the Orlando gay club terror attack.
( Alisdare Hickson / Getty )
( Alisdare Hickson / Getty )
Produced by Dana Roberson