The father of a slain Dallas cop sues Black Lives Matter. His lawsuit alleges that the group's message inspired the deadly sniper attack that killed five officers in Dallas.
Experts say Johnson's medical path is the determining factor in comprehending his mindset on the fateful night of July 7, when he opened fire at a peaceful anti-police brutality rally.
According to the FBI, Johnson was armed with an SKS semiautomatic rifle and wore ballistic body armor with plates. The SKS is a Soviet-designed military rifle first introduced in 1945.
