In what circumstances will a defendant be able to proceed with a plan to kill a police officer?

In Mendoza, the defendant did not initiate an encounter with an officer, but quickly formulated a plan to kill the officer as soon as the defendant learned the officer was going to conduct a weapons search. Planning was demonstrated by the defendant using another detainee as a shield and approaching the officer without attracting attention. Preexisting motive was also quickly formed because as the officer approached the defendant and his friends, the friends told defendant to run away but he chose instead to stay and later attack the officer. The manner of killing, a single shot to the head, further evidenced the defendant's intent to kill. (People v. Mendoza, supra, 52 Cal.4th at pp. 1071-1072.)