Massachusetts defendants are entitled to the criminal record for each witness that will testify for the prosecution at trial. This is part of the mandatory discovery required by Rule 14 of the Massachusetts Rules of Criminal Procedure.

According to Rule 14(D),

At arraignment the court shall order the Probation Department to deliver to the parties the record of prior complaints, indictments and dispositions of all defendants and of all witnesses…within 5 days of the Commonwealth’s notification to the Department of the names and addresses of its witnesses.

The Supreme Judicial Court has noted that

The proper route for the defendant to obtain prior convictions of prospective witnesses for the Commonwealth is by requesting the judge to order the probation department to produce them.

Commonwealth v. Martinez, 437 Mass. 84, 95 (2002)

However, at least here in western Mass, many probation departments will release any criminal records covered by Rule 14 to the defendant if the prosecutor signs an assent. Each court and each probation department throughout the Baystate may handle witnesses’ records slightly differently.