Nassau police are opening an investigation into the way officers handled a domestic disturbance call allegedly made the night before a New Cassel woman was found dead in her home.

Police say Joanna Bird, a single mother of two, was stabbed to death last Thursday in her home by her ex-boyfriend, Leonardo Valdez-Cruz. Sharon Bird, one of Bird's sisters, says the family called police on Valdez-Cruz more than half a dozen times last week, including the night before she was found dead. The family says he was harassing her. Bird?s family members say police gave Valdez-Cruz a warning to leave Bird?s house and said if he returned, they would arrest him. The family says if Valdez-Cruz had been arrested that night, their loved one would still be alive.

Cops are neither admitting nor denying that officers even responded to the house that night at all. ?Those are all matters that we are looking into,? Nassau Detective Lt. Kevin Smith says. ?To see if the police were in fact called, whether they were called by the victim, whether or not these circumstances really existed. We have to investigate.?

According to prosecutors, 23-year-old Leonardo Valdez-Cruz is still being held at NUMC undergoing psychiatric evaluation. He has been charged with Bird?s murder and was a no-show in court Tuesday.

Nassau County District Attorney Kathleen Rice says Bird had an order of protection against her alleged killer.

Bird?s family is planning her funeral.