PORTLAND — The six Verrill Dana partners who dealt with John D. Duncan’s thefts from the law firm failed to have measures in place to deter unethical conduct by its lawyers, the Maine Supreme Judicial Court ruled today.

The state’s high court found that the lawyers serving as the firm’s executive committee – David Warren, James Kilbreth III, Eric Altholz, Mark Googins, Roger Clement Jr. and Juliet Browne – violated an ethics rule about the responsibilities of partners and supervisory lawyers. The rule requires partners to make reasonable efforts for their firms to have policies to make their lawyers conduct themselves responsibly.

Before his thefts were discovered in 2007, Duncan enjoyed a reputation for integrity and as one of the state’s best lawyers for wills, trusts and estates. An audit found that Duncan had stolen about $300,00 from clients and the firm.

After presiding over a disciplinary hearing last year, state Supreme Court Justice Donald Alexander ruled that the six lawyers broke no ethics rules in their response to the Duncan matter. Alexander found that the lawyers had acted in good faith based on the information they then had. The Maine Board of Bar Overseers, whose lead counsel alleged a variety of ethics violations, appealed Alexander’s ruling to the Supreme Court.

The Supreme Court agreed with Alexander that there was no violation of an ethics rule on when a lawyer is required to report another lawyer’s misconduct. The court is sending the matter back to Alexander for a judgment consistent with its opinion and appropriate sanction.

Duncan served two years in federal prison after pleading guilty to theft and tax evasion. He was disbarred for life.