PORTLAND — A judge today heard closing arguments in a disciplinary hearing against six lawyers from the Verrill Dana law firm, related to the handling of the John D. Duncan scandal three years ago.

Testimony in the case was heard Monday, Tuesday and Wednesday at Lewiston District Court. Justice Donald Alexander of the Maine Supreme Judicial Court listened to closing arguments today at Cumberland County Superior Court.

Alexander is expected to review the evidence and issue a written decision sometime in the coming weeks.

Verrill Dana’s former managing partner, David Warren, and five lawyers who served on the firm’s executive board in 2007, are defending themselves against alleged ethics violations.

The Maine Board of Bar Overseers, which governs the conduct of lawyers, filed the complaints. J. Scott Davis, lead counsel for the board, alleges the Verrill Dana lawyers, when they learned about misconduct by Duncan in June 2007, should have immediately reported the matter to the ethics board and launched a thorough investigation.

Davis seeks professional sanctions, which could range from a simple reprimand to disbarment, against Warren; James Kilbreth III, who chaired the firm’s executive board at the time; and Eric Altholz, Mark Googins, Roger Clement Jr. and Juliet Browne, lawyers who served on the firm’s executive board.

The lawyers say they handled the situation appropriately, broke no ethics rules and should not be sanctioned. They say they were deceived by Duncan, and believed his story that he had only misappropriated money that was supposed to have been deposited into Verrill Dana’s general account.

Because they believed Duncan had not broken any laws, but had simply violated the firm’s partnership agreement, the Verrill Dana lawyers argue that they had no duty to report him to the Board of Bar Overseers. An audit of Duncan’s books later in 2007 showed he had stolen roughly $300,000 from clients and the firm over the previous decade.

Duncan ultimately pleaded guilty to theft and tax evasion. He served two years in federal prison and received a lifetime disbarment, the toughest punishment ever imposed on a Maine lawyer.