The General Laws are hereby amended by inserting after section 20H of chapter 90 of the General Laws the following section:-

Section 20I. 

(a)  Evidence obtained during a traffic stop shall be inadmissible in any criminal proceeding if the evidence is unrelated to the traffic violation that was the basis for the stop, unless the officer had reasonable suspicion or probable cause to believe that the operator or passenger of the vehicle was engaged in an act that constitutes a felony or a misdemeanor prior to initiating the stop.

(b) In any motion to suppress evidence under this section, the burden shall be on the commonwealth to prove by a preponderance of the evidence that reasonable suspicion or probable cause of criminal activity existed prior to the initiation of the traffic stop.

(c) Nothing in this section shall be construed to limit the authority of law enforcement to enforce the traffic laws of the commonwealth. Law enforcement officers may issue citations, warnings, or make arrests for violations of traffic laws; provided, however, that such enforcement shall not serve as a pretext for investigating unrelated criminal activity.

(d) (1) Any evidence obtained in violation of this section shall be suppressed and shall not be admissible in any criminal proceeding in the courts of the commonwealth.

(2) Any individual subjected to a traffic stop in violation of this section may pursue all civil remedies available under state or federal law, including but not limited to claims for injunctive relief or monetary damages.