St.2010, c.256, s.125, effective this week, allows prosecutors to seek pretrial detention under MGL c.276, s.58A for anyone charged with a felony for possession of a firearm under MGL c.269, s.10 (a), (c) or (m) (with some exceptions).
The law was enacted after the SJC ruled last year in Comm. v. Young, 453 Mass. 507, that unlicensed possession of a firearm did not qualify "as a predicate offense pursuant to G. L. c. 276, § 58A, which allows the Commonwealth to seek pretrial detention of individuals accused of certain serious offenses."
More information on criminal procedure is available at Mass. Law About Criminal Law and Procedure.