Olivia McDonald was born at St. Helen's Home for Unwed Mothers and adopted by Luca and Audrey Santanello. Her birth date and birth parents are not known. The family lived in Oxnard, CA and included her brother, Dominick Santanello. As of 2016 she lived in the same house where she grew up.
In October 2016 she was contacted by Harry Bosch regarding Dominick. She told Bosch what she could remember about her brother, showed him some photos and allowed him to look at some of Dominick's personal items that were stored in her attic. She allowed him to take a toiletry kit to check for a DNA sample.