Defense first; notify second. You can't dial 911 if youre preoccuppied fighting and they can't get there fast enough. Defend yourself and live to call 911. Shooting through a door and the perp's actions dictate legal options of recourse.
Eph6:12 For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms.13Therefore put on the full armor of God