16-year-old Ethan Couch killed four strangers on Father's Day weekend in a drunk driving crash that also left one of his friends paralyzed. He faced the possibility of 20 years behind bars. But a judge sentenced him to probation after his lawyers argued that Couch was a victim of his family's wealth. An expert the defense put on the stand called it "affluenza." Randi Kaye has more on what happened on the night of the crash.