The Appellate Division in Brooklyn said former White Plains Mayor Adam Bradley - once an up-and-coming Democratic star - "was deprived of a fair trial" and deserves a new one.
Bradley was convicted by a judge in 2010 of attempting to assault his wife by slamming a door on her fingers. He was also convicted of harassment. His wife, Fumiko Bradley, was the main witness against him.
The appeals court ruled that Bradley should have been allowed to call witnesses who might have cast doubt on his wife's testimony. Those witnesses were expected to testify that Fumiko Bradley had stated in the past that the door had been shut on her hand accidentally.
The trial judge said that testimony would have been "too remote or speculative."
But the appeal judges said it would have been "relevant to the issue of the wife's credibility."
A call to Bradley's attorney, Amy Bellantoni, was not immediately returned.
Lucian Chalfen, a spokesman for the Westchester County district attorney's office, said prosecutors are deciding whether to appeal.
After Bradley's conviction, he repeatedly called the decision unfair and resisted calls for his resignation. But he left office in February 2011, saying, "I can no longer allow the circumstances of my personal life to be a distraction" from the city's needs.
He insisted he was not acknowledging guilt but needed time to focus on "exonerating my name and reputation."
"It is my hope that at the end of this judicial process, the truth will come out," the mayor said.
He was then sentenced to three years of probation.
Bradley and his wife have two children. They are in divorce proceedings.
Bradley was in just his second month as mayor when he was arrested. The former state assemblyman had been considered a politician on the rise.
It was not clear what effect Monday's decision will have on Bradley's current court case, in which he's accused of violating a court order by telephoning his wife. Bradley says the calls were accidental "pocket dials."
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