She pleaded not guilty in First District Court in Hempstead on Saturday.

Image Jennifer E. Gross was arrested on Friday. Credit... Nassau County Police Department

“They had a very contentious relationship with violence and stealing of money,” Detective Lt. Stephen Fitzpatrick said at a news conference on Saturday. “In this particular case, when she didn’t get her money she wanted, she beat him and killed him.”

Lawyers for Ms. Gross could not be reached for comment.

The police described Ms. Gross as a drifter who survived on odd jobs and money given to her by various men. Her sporadic relationship with Mr. Coppola lasted for nearly 20 years, they said.

But over the years, their relationship had become increasingly volatile — with large sums of money as a central dispute.

In 2012, Mr. Coppola sued Ms. Gross and her ex-husband, David A. Gross, a former district court judge in Nassau County, who was sentenced to 33 months in prison for money laundering in 2007.

Mr. Coppola claimed that Ms. Gross owed him $276,000, and the lawsuit aimed to enforce a divorce agreement that he believed existed between Ms. Gross and Mr. Gross. By enforcing the settlement, Mr. Coppola believed Ms. Gross could pay him the money she owed him, according to court documents.