Authorities say a Georgia woman repeatedly stabbed her 86-year-old housemate in New Jersey, but they are not sure of a motive in the case.

Police responded to the Cedar Grove home around 4 a.m. Monday after the victim's husband reported his wife had been attacked in her bedroom. She had been stabbed 15 times and was taken to a hospital, where she remains in critical condition.

The alleged assailant, Tanya Spears, was found in a first-floor guest bedroom. The 60-year-old is charged with criminal attempt to commit murder, aggravated assault and two weapons charges.

It's not known if Spears has retained an attorney.

No other injuries were reported in the attack, which remains under investigation.