Is 16-year-old Philip Chism insane, or did he deliberately and coldly kill his 24-year-old math teacher, Colleen Ritzer? That's what jurors in Salem will be weighing when they begin their deliberations, expected Friday. Chism's trial has surfaced some of the most contentious issues in American jurisprudence today — whether teens should be tried as adults, whether their developing brains should be taken into account, and whether they should should face life sentences.