SECTION 1.  Chapter 265 of the General Laws is hereby amended by inserting after section 15C the following new section: -

Section 15D.  As used in this section, “law enforcement officer” shall mean any officer of a municipal police department, the department of the state police or the Massachusetts Bay Transportation Authority police department.

Whoever commits an assault or an assault and battery upon a law enforcement officer by discharging a firearm, rifle, shotgun, sawed-off shotgun, assault weapon, or covert weapon while said officer is engaged in the performance of duties, and who knows or has reason to know that the individual is a law enforcement officer shall be punished by a term of imprisonment not less than 10 years up to life imprisonment in the state prison. No sentence imposed under the provisions of this paragraph shall be suspended nor shall it be for less than a mandatory minimum term of imprisonment of 10 years and a fine of not more than $150,000 may be imposed but not in lieu of the mandatory minimum term of imprisonment, as established herein.  Prosecutions commenced under this section shall neither be continued without a finding nor placed on file.