Updated

Massachusetts authorities have planned a news conference to discuss a "major development" in the nearly 50-year-old slaying of a woman that was attributed to the Boston Strangler.

Nineteen-year-old Mary Sullivan was found strangled in her Boston apartment in January 1964. She was the last of 11 women whose deaths were attributed to the Boston Strangler.

Albert DeSalvo confessed to the killings but was never convicted. He died in prison in the 1970s.