The body of 58-year-old Walter Boland was discovered by a jogger Friday near a recreational path alongside the Wantagh State Parkway.
State Police announced Saturday that they had arrested Boland's 56-year-old ex-wife, Nancy. She is charged with manslaughter.
Her lawyer, David Besso, called Walter Boland "an abuser" and said the couple had been to court previously accusing each other of domestic violence.
Authorities said Boland was stabbed once in the abdomen during a fight at the couple's home late Wednesday.
He never got medical attention, and died Thursday.
Police said Nancy Boland loaded his body into a car and dumped it early Friday.