MPG: Gateway

Welcome to MASSACHUSETTS CRIMINAL LAW: A PROSECUTOR'S GUIDE Online.

On this site, you will find the full text of the 44th edition of the Prosecutor's Guide. The Guide presents a timely and comprehensive analysis of Massachusetts criminal law and its practice in the courts of the Commonwealth and cites to over 7,000 Massachusetts criminal decisions by the Supreme Judicial and Appeals Courts. It is fully updated each fall and during the year as new developments in the law warrant. Please consult our What's New page for the most recent changes.

The text also cites and discusses significant criminal law cases decided by the Supreme Court, the federal Courts of Appeals, and state appellate courts from around the country. The principal focus, however, is on Massachusetts criminal law and its practice in the courts of the Commonwealth.

Access to the Guide is by annual subscription. If you are not yet a subscriber, please take the tour of a sample chapter from the Guide.

Please Note: If you are an employee of the Massachusetts Trial Court or an Assistant District Attorney, you have unlimited access to the Prosecutor's Guide web site thanks to licenses purchased on your behalf by the Massachusetts Trial Court Law Library and the Massachusetts District Attorneys Association, respectively. Please contact your office law library for access instructions. In the case of ADAs, access to the Guide is through your account on the New York Prosecutors Training Institute website.

Also law students at the following institutions have access through your school Law Library: Harvard, Suffolk, Boston College, Northeastern, Western New England School of Law, New England Law | Boston, Boston University, and the University of Massachusetts.

Please note:
10/7/25: "Identification Evidence" has been revised in anticipation of the expected amendments to the Model Jury Instructions on Eyewitness Identification. 10/3/25: The chapter on "Joint Venture", "Multiple Defendants", and the "Bruton Rule" has been revised to consider the impact of the Supreme Court's 2024 decision in Smith v. Arizona on the Massachusetts common-law evidentiary rule governing the admissibility of substitute expert testimony, as assessed by the SJC in Commonwealth v. Gordon, 496 Mass. 554 (2025). 9/8/25: "Criminal Trespass" and "Motor Vehicle Offenses" have been revised, the latter to include important new cases on the already relaxed meaning of "operating" a motor vehicle for purposes of an OUI conviction as well as an important new case on the nonconsensual extraction of blood samples, Commonwealth v. Zucchino, 493 Mass. 747 (2024), which trims back earlier cases which appeared to misread the aggravated drunk driving statutes. Please see What's New for further details.

Please note:

10/7/25: "Identification Evidence" has been revised in anticipation of the expected amendments to the Model Jury Instructions on Eyewitness Identification.

10/3/25: The chapter on "Joint Venture", "Multiple Defendants", and the "Bruton Rule" has been revised to consider the impact of the Supreme Court's 2024 decision in Smith v. Arizona on the Massachusetts common-law evidentiary rule governing the admissibility of substitute expert testimony, as assessed by the SJC in Commonwealth v. Gordon, 496 Mass. 554 (2025).

9/8/25: "Criminal Trespass" and "Motor Vehicle Offenses" have been revised, the latter to include important new cases on the already relaxed meaning of "operating" a motor vehicle for purposes of an OUI conviction as well as an important new case on the nonconsensual extraction of blood samples, Commonwealth v. Zucchino, 493 Mass. 747 (2024), which trims back earlier cases which appeared to misread the aggravated drunk driving statutes.

Please see What's New for further details.