The Trump shooter's motive remains a mystery, even to those who knew him

Law enforcement search an address in Bethel Park, Pennsylvania, in connection with the attempted assassination of Donald Trump. They are yet to uncover a clear motive behind the shooting.

The Washington Post via Getty Images

• A shooter armed with an AR-15 rifle opened fire on Donald Trump during a rally in Pennsylvania.
• The FBI said it is working "tirelessly" to identify a motive behind the attempted assassination.
• Acquaintances of the man who conducted the shooting said they were in shock.