Being a principal in a crime, by virtue of being an aider and abettor pursuant to Penal Code section 31, and being an accessory to that crime pursuant to Penal Code section 32 are not mutually exclusive offenses as a matter of law. But in order to find someone to be an accessory after the fact to a felony, in the commission of which the person is also a principal by virtue of his or her having aided and abetted its commission, the acts constituting that felony must have ceased at the time of the conduct that violates section 32. Otherwise, the conduct of aiding or concealing a principal with the intent that he or she should avoid arrest is subsumed into the conduct of aiding the commission of the crime with the intent or purpose of facilitating commission of the offense. Here Malcolm M. was with Hakkim when Hakkim possessed an assault weapon that was used to shoot at another and continued to be with him until stopped by police at which time Malcolm M. placed his feet over the weapon in an attempt to conceal the weapon. Malcolm M. was liable for the possession of the weapon on an aider and abettor theory as he had acted as a lookout. Because the possession of the weapon by Hakkim was a continuing offense and not completed when Malcolm attempted to conceal the weapon, he could not also be found liable as an accessory to the possession charge.