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. 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. In addition, this online text is linked to a database of Massachusetts court decisions maintained by the Trial Court Law Libraries at masscases.com.

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:
3/16/25: "Narcotics Offenses" has been updated to note new cases and statutory developments. Of particular interest is the Supreme Court's recent decision in Diaz v. United States, which considerably loosens any restraints on the ability of an expert witness to opine on the ultimate issue of a defendant's guilt or innocence. 3/4/25: "Public Order Offenses" has been revised to note new case law further clarifying the procedures to follow in dealing with prosecutions of "second chance" juvenile misdemeanors, so-called "true" threats, instances of virtual lewd behavior, sex trafficking, and claims of selective prosecution. Please see What's New for further details.

Please note:

3/16/25: "Narcotics Offenses" has been updated to note new cases and statutory developments. Of particular interest is the Supreme Court's recent decision in Diaz v. United States, which considerably loosens any restraints on the ability of an expert witness to opine on the ultimate issue of a defendant's guilt or innocence.

3/4/25: "Public Order Offenses" has been revised to note new case law further clarifying the procedures to follow in dealing with prosecutions of "second chance" juvenile misdemeanors, so-called "true" threats, instances of virtual lewd behavior, sex trafficking, and claims of selective prosecution.

Please see What's New for further details.