Dorothy Arnold — Disappearance Profile

Dorothy Harriet Camille Arnold (born 1 July 1885) was the daughter of a wealthy Manhattan importer and a graduate of Bryn Mawr College. On the morning of 12 December 1910 she told her mother she was going shopping and left the family home on East 79th Street at around 11 a.m., declining her mother's offer to accompany her.

Her movements that day are partly documented: she charged a box of chocolates to her account at a Fifth Avenue store around midday, then walked south to Brentano's bookstore, where she bought a book. She was seen by a store cashier and by a friend on Fifth Avenue, told the friend she intended to walk through Central Park before returning home, and was never reliably seen again.

When Arnold did not return for dinner, her family grew alarmed but, anxious to avoid publicity, hired private investigators and did not report her missing to police until roughly six weeks later. By then any trail had gone cold. The case was investigated by the New York Police Department and attracted national press attention; it has never been resolved and the file remains open.

Several leads and claims surfaced but none was substantiated: a postcard signed "Dorothy" that her father believed was a hoax; a San Francisco jeweller who claimed to have served a woman he believed was Arnold; and a 1916 claim by a convicted felon. These accounts are unverified and were never confirmed. Ordinary explanations considered include a fatal accident or foul play, and voluntary departure.

No remains, no confirmed sighting after 12 December 1910, and no verified explanation. The case is commonly cited as the oldest open missing-person case in the United States.

• "Disappearance of Dorothy Arnold," Wikipedia
• National Geographic — Dorothy Arnold

Status as of June 2026: Missing / unsolved. Open NYPD case.