Origin of attack ad remains unknown 4 months after election 3/2/2005, 5:44 p.m. ET By DAVID EGGERT The Associated Press LANSING, Mich. (AP) — Four months after the November election, the identity of whoever backed nearly $400,000 worth of attack ads against a Michigan Supreme Court justice remains a mystery. A group that calls itself Citizens for Judicial Reform has yet to file a postelection report outlining its spending or disclosing its financial backers. The department of state notified the group's treasurer Feb. 10 that it hadn't submitted a report due Jan. 31, and the group has been accruing late...