A witness to the horrific shooting rampage in the Colorado movie theater called it "the longest minute" of his life. One can only imagine. But the second longest minute may be the waiting for someone -- the authorities, the pundits, the doctors -- to tell us "why" these killings happened. Police say James Holmes, a 24-year-old graduate student in a neurosciences program, called himself the Joker and rained merciless bullets on strangers watching a Batman movie. Why?