Who is Robert Bowers, the Pittsburgh synagogue shooting suspect?

Two hours before a gunman burst into the Tree of Life synagogue and opened fire during a Shabbat religious service, Bowers posted on chat site Gab.com about the Hebrew Immigrant Aid Society (HIAS), a non-profit that helps Jewish refugees relocate to the United States."HIAS likes to bring invaders in that kill our people.Screw your optics, I'm going in," wrote Bowers, a heavy-set, white male.