Mass. Gen. Laws ch. 54, § 80

Except as authorized by this chapter, no voter, election officer or other person shall place on a ballot any mark by which it may be identified; nor shall any person place a mark against any name upon a ballot not cast by himself; nor shall any election officer engaged in counting ballots, except the election officer or officers actually entering the count of ballots cast on tally sheets, hold in either hand during the counting of ballots a pen, pencil or other marking device. Election officers shall use only red pencils or red ink in recording or tabulating the vote in election precincts.