Prosecutors say a 100-year-old man apparently killed his wife with an ax as she slept in their northern New Jersey home, then killed himself in the bathroom with a knife.

But it's still not clear what sparked the murder-suicide late Sunday in Elmwood Park.

Bergen County Prosecutor John Molinelli says there was a "history of domestic issues" between Michael Juskin and his 88-year-old wife, Rosalia. But he said a motive for the attack remains under investigation.

Police officers found the couple in their Spruce Street home after relative — who was not in the home — called authorities. The deaths were made public Monday.

Authorities do not believe anyone else was in the home when the attack occurred.