A 70-year-old woman shot and killed her former daughter-in-law in the parking lot of the preschool where the young teacher worked, Utah police said Saturday.

Mary Nance Hanson is accused of firing multiple shots into the car of Tetyana Nikitina, 34, as she prepared to leave Friday from the Salt Lake Community Action Program Head Start school.

Police said the suspect called 911 and was waiting at the scene when officers arrived. When asked why she had fired the shots, she told a 911 dispatcher, "I don't know, and that's all I'm going to say."

Nikitina, a single mother of two, was behind the steering wheel when officers arrived. She was taken to a hospital, where she was pronounced dead.

According to court records obtained by the Deseret News, Nikitina filed for divorce from Dale Jankowski in February 2005. Police say they believe Jankowski is Hanson's son.

Records show that twice after the divorce, in August 2005 and in January 2006, Nikitina filed for protective orders against Jankowski, claiming cohabitant abuse.

Unified Police Lt. Don Hutson told the Deseret News they can't identify a specific event that triggered the shooting. He said there were ongoing custody battles, "but that's nothing new."

Hanson, a concealed weapons permit holder, was booked into the Salt Lake County Jail on suspicion of murder. She lives in Taylorsville, as did Nikitina.

Salt Lake Community Action Program Head Start is a federally funded, comprehensive early childhood development program serving low-income children between the ages of 3 and 5.

Nikitina had been with the school for five years as an assistant teacher.

Hutson said no children attend classes on Fridays, but teachers were there for training.