Nancy Boland, 57, pleaded guilty in January to first-degree manslaughter, aggravated criminal contempt, tampering with physical evidence and other charges.
"This was not self-defense, and it was no accident," Nassau District Attorney Kathleen Rice said in a statement. "Nancy Boland killed her ex-husband, dumped his body on the side of the road, and then lied to anyone who asked."
While free on bail in January, Boland assaulted her 83-year-old mother with the woman's aluminum walking cane. Boland pleaded guilty in that case in February, and Suffolk County prosecutors agreed that a sentence of 7 years in prison for assault, followed by 5 years of probation, would run concurrently with the sentence in Nassau.
Boland's mother, Marie Wieden, was treated for bruises and a broken nose at Southside Hospital in Bay Shore.
Rice said Boland and her ex-husband, Walter Boland, with whom she still lived in North Bellmore, got into an argument on Nov. 16.
The argument escalated, and Boland claimed her ex threatened her with a sharp-bladed instrument, Rice's office said.
Nancy Boland said she grabbed it out his hand and stabbed him with it once in the abdomen, driving it upward and four inches deep, prosecutors said.
Boland, against whom her ex-husband had a valid order of protection, told police that he refused to be taken to the hospital, and that she left him at home to go to work the following day. When she returned home, she found the victim unresponsive. After dressing him and attempting to feed him, she concluded that he was dead, waiting until after dark to then drag his body to her mother's car.
Boland later told family, friends and co-workers that the victim had stormed off after an argument and hadn't returned. When his body was discovered, Boland told them that she was worried it might be her ex-husband.