Characteristics of a potential mass shooter 

There are several different types of behaviors that may be precursors to potential violence towards others and should not be ignored. Virtually all individuals who have committed mass shootings in the past have exhibited these types of behaviors. 

Behaviors:
Anti-Social Behavior. Anti-social people have a hard time getting along with other people. It might vary from a refusal to interact with colleagues to blatant harassment. An antisocial personality may distance themselves from their workplace at times. In other cases, a person may make offensive statements, disrespect authority, or even go beyond the bounds of acceptable conduct.
 
Some individuals may exhibit Vindictiveness. People that are potentially dangerous have a proclivity for vengeance. They not only blame others for their troubles, but they also display a desire for retaliation. They may express their vengeance in relatively moderate ways, such as "They'll get theirs eventually," or "They'll get theirs someday." In other circumstances, their words might have a more menacing tone, such as "I'll show them.” 

Sometimes individuals may exhibit Extreme Paranoia and believe and that people are attempting to harm them. Extreme Paranoia individuals are fundamentally distrustful and apprehensive, believing there is a plot to undermine or even destroy them.

Persistent Anger Everybody gets upset now and then. However individuals that exhibit uncontrollable rage is a solid predictor of future violence.

Violent Thoughts. individuals that are obsessed with violence will often let people know what they're thinking.  When someone celebrates rather than commiserates after hearing about a mass shooting on the news; When someone jokes about shooting other people; When someone casually mentions blowing someone's brains out, they are offering you a valuable look inside their minds. 

If you know someone who exhibits these behaviors and believe they intend to cause harm to others, you must take action. ​Contact the authorities so they can intervene and get that person the help they need.