You pull the trigger, and feel as though you were punched on the arm, almost collapsing. Unused to the recoil of a shotgun, it takes you a moment to regather your bearings.
But the sound has attracted more attention than you expected. You pump the shotgun, preparing to fight your way out; the first cop whose head comes around the corner has it forcibly removed.
You receive a steady stream of bullets in return. The first two hit both your shoulders; but you barely have time to scream before a third buries itself between your eyes.