Bianca was last seen at approximately 6: 15 p.m. on March 10, 2005, when her mother dropped her off on McIntosh Hill Road in Foley, Missouri, about a mile from their home. She had been struggling with anger management issues, and on the night of her disappearance, she became upset over household chores.

Following advice from her therapist, her mother had previously used a strategy where Bianca would walk home alone to help manage her emotions. Bianca had found the approach helpful and requested to do it again that evening, asking to be dropped off farther from home than before. She never arrived home and has not been heard from since. Despite an extensive search, no trace of Bianca was found. Authorities now believe she may have been abducted. She had no history of running away. Investigators ruled out her immediate family as suspects after both her mother and her mother's live-in boyfriend passed polygraph tests, and her biological father was thoroughly interviewed.