Toronto Attack Revives Debate Over ISIS’ Call to Arms to the Mentally Ill

After a 31-year-old man used a cargo truck to crush 86 people to death on the promenade in Nice, France, his distraught father rushed to tell reporters his son had once suffered a nervous breakdown. When Omar Mateen used a Sig Sauer MCX semiautomatic rifle to gun down 49 people at an Orlando nightclub, relatives described him as bipolar.