(a) A person is guilty of assault in the second degree with a firearm when he commits assault in the second degree as provided in section 53a-60 , and in the commission of such offense he uses or is armed with and threatens the use of or displays or represents by his words or conduct that he possesses a pistol, revolver, machine gun, shotgun, rifle or other firearm. No person shall be found guilty of assault in the second degree and assault in the second degree with a firearm upon the same transaction but such person may be charged and prosecuted for both such offenses upon the same information.
(b) Assault in the second degree with a firearm is (1) a class D felony, or (2) if the offense resulted in serious physical injury, a class C felony, for which, in either case under subdivision (1) or subdivision (2) of this subsection, one year of the sentence imposed may not be suspended or reduced by the court.