Warning: This story contains graphic details.

ELMWOOD PARK, N.J. -- Authorities say police had responded on at least three occasions to the home of an elderly couple who died over the weekend in a murder-suicide at their northern New Jersey residence.

Autopsies determined 100-year-old Michael Juskin killed his wife, 88-year-old Rosalia, with an axe while she lay in bed Sunday, Bergen County Prosecutor John Molinelli announced Tuesday.

Authorities say he then took his own life by cutting his wrists.

A motive for the attack remained under investigation. Family members have said Michael Juskin suffered from dementia.

The Juskins were found dead at their Elmwood Park home Monday morning after a relative called authorities.

Elmwood Park police told The Record that officers had responded on at least three occasions since 2012 to the couple's home.

The latest call came Jan. 13 when Rosalia Juskin said her husband was confused and locked her in the basement. She told police she was having difficulty caring for him and police contacted the county's adult protective services. Authorities said they found nothing at the time to suspect Juskin would violently attack his wife.

Before that, police responded in September 2013 when Rosalia Juskin claimed her husband was harassing her and to a March 2012 emergency call when they found him unstable and took him to a hospital for evaluation.

A neighbour told The New York Times that Michael Juskin knocked on her door about a month ago, asking for a ride to see a lawyer about a divorce.

"He was very unhappy; he thought his wife was taking his pension money," Alejandra Gonzalez told the newspaper. "He might have thought she was cheating on him."

She said her fiance took the elderly man as a favour, and the lawyer told Juskin just to let it go and enjoy the rest of his life, Gonzalez said.