PORTLAND – A retired merchant mariner who was hit with a 90-day jail term for evading Maine income taxes says state revenue agents have been unfairly targeting graduates of Maine Maritime Academy.

Frank Greenleaf, 57, of Milford was found guilty in Penobscot County Superior Court after the state argued that he falsely claimed to have been a resident of New Hampshire, which has no income tax.

Greenleaf, who maintained that he was living aboard a ship during the years in question, said the state was going after merchant mariners who, like himself, attended the Castine academy.

“Maine is hurting for money and they see us as an easy target,” said Greenleaf, who is considering whether to appeal.

William Baghdoyan, who prosecuted the case, acknowledged that the state focuses on certain professions where tax evasion is rife, including airplane pilots, fishermen, oil-rig and construction workers, and computer consultants.

Jerome Gerard, acting state tax assessor and head of Maine Revenue Services, said he is aware of concerns about the investigation of Maine Maritime graduates but says they are treated no differently from other taxpayers.

“We do searches for nonfilers and comb various different information reports. We are pretty reasonable in the way we ferret out nonfilers,” he said.

Baghdoyan said Greenleaf falsely claimed he was a New Hampshire resident in 1996 and 1997. Greenleaf, he said, used a friend’s Rochester, N.H., address, obtained a New Hampshire driver’s license and registered to vote there while living in Maine.

Justice Thomas Warren, who tried the case without a jury, sentenced Greenleaf to 18 months in jail with all but 90 days suspended, and two years of probation.

Conditions of probation include 200 hours of community service and payment of $26,851 in restitution and a $2,000 fine.