Student A : In this case it is obvious that D is a principal to this crime. He actually makes the preparation by inviting E and F to join in and make a plan to kill A. I would think that the commission of the crime starts from when D, E, and F arrive at the office building and take up their positions. The act of D’s shooting at A makes it clear beyond reasonable doubt that D intends to kill A. But he has not succeeded as intended. The crime of murder is not completed. D is only guilty as a principal at attempted murder. Had he succeeded in killing A, he would have been guilty of murder.