PONTIAC, Mich. — Accused Oxford High School shooter Ethan Crumbley appeared briefly before a judge Thursday for a pretrial placement hearing but his situation will not change. Crumbley, 15, has been in the county jail since he was charged after the Nov. 30 mass shooting at the school; four students died and seven others were wounded including a teacher. Crumbley’s attorneys plan an insanity defense for their young client, who faces up to life in prison if convicted as charged. He remains in isolation in the Oakland County Jail, separated from adult prisoners. He appeared for Thursday’s hearing…