A person is guilty of robbery in the first degree when he forcibly steals property and when, in the course of the commission of the crime or of immediate flight therefrom, he or another participant in the crime: 1. Causes serious physical injury to any person who is not a participant in the crime; or 2. Is armed with a deadly weapon; or 3. Uses or threatens the immediate use of a dangerous instrument; or 4. Displays what appears to be a pistol, revolver, rifle, shotgun, machine gun or other firearm; except that in any prosecution under this subdivision, it is an affirmative defense that such pistol, revolver, rifle, shotgun, machine gun or other firearm was not a loaded weapon from which a shot, readily capable of producing death or other serious physical injury, could be discharged. Nothing contained in this subdivision shall constitute a defense to a prosecution for, or preclude a conviction of, robbery in the second degree, robbery in the third degree or any other crime. Robbery in the first degree is a class B felony.
New York Legal Code