The Northwestern District Attorney's office has apparently joined the investigation into a false cocaine allegation made by a sitting state rep against her Republican opponent.  The Worcester Telegram and Gazette reports that the D.A. has launched a separate investigation into the decision by State Rep Denise Andrews to report an alleged cocaine sale at the home of her Republican opponent, Susannah Whipps Lee.  The report was deemed unfounded by Athol Police, and is also the subject of an investigation by the state Attorney General's office.  The first debate of the campaign takes place Wednesday night in Templeton.