Dorothy was last seen at her home in Nashua, New Hampshire on October 3, 1973. At the time of her disappearance, she lived in the 100 block of Kinsley Street with her husband of two years, Kenneth N. Bois, and their daughter. Kenneth said they were watching television that evening and he fell up at 11:30 p.m. When he woke up, Bois was gone. He reported her missing at 4:13 a.m. the next day. She has never been heard from again.

Dorothy left behind all her belongings, except her pocketbook and a white flowered beaded change purse. Her mother stated she would have contacted her family if she'd left on her own, but none of her relatives have heard from her since 1973. Dorothy was reportedly under great stress at the time of her disappearance due to health problems with her child. She told her mother she was afraid for her life. Kenneth had filed for divorce the month before she vanished, citing irreconcilable differences. The divorce was granted after Dorothy's disappearance and he remarried in 1974. He is now divorced from his second wife.

Dorothy dropped out of high school in her sophomore year after she became pregnant. She had a son and raised the baby together with her mother, and he lived with her mother when Bois disappeared. Police reopened the investigation into her disappearance in 2007. Her parents are deceased and the whereabouts of her son are unknown. Foul play is suspected in her case, which remains unsolved.