SJC hears challenge to prosecution of ex-state senator; defense cites legislative immunity, disputes grand juror excusal

BOSTON — In oral argument before the Supreme Judicial Court, defense attorney Michael Walsh asked justices to dismiss criminal charges against former state Sen. Dean Tran, arguing that legislative immunity and legislative privilege bar prosecutors from using acts or staff communications tied to legislative duties as evidence. Assistant Attorney General Tara Johnson told the court the motion judge should be affirmed and that Tran had not shown a meritorious claim of immunity.

Walsh, representing Tran, told the court “it is our first contention that this violates the general tenure of legislative immunity,” framing the defense around three themes: (1) legislative immunity, (2) legislative privilege for internal legislative communications, and (3) alleged misconduct by a grand juror. Walsh said the remedy, in his view, would have been to seek a formal opinion from the Senate or House ethics committee rather than rely on grand‑jury evidence: “the answer was to go to the House Ethics or the Senate Ethics Committee and get an opinion from them instead of bringing an indictment.”

Johnson, speaking for the Commonwealth, said the motion judge’s ruling should be upheld. “The motion judge’s decision should…