The defendant in a prosecution for writing or publishing a libel may introduce in evidence the truth of the matter contained in the publication charged as libellous, and the truth shall be a justification, unless actual malice is proved.
Mass. Gen. Laws ch. 278, § 8
Justification in libel cases
Official source: Massachusetts Legislature. Reproduced from public-domain Massachusetts statutes; confirm against the official source for the current text. Not legal advice.