https://parade.com/1194770/marynliles/unsolved-mysteries/
26. The Disappearance of Dorothy Arnold
Dorothy Harriet Camille Arnold was a wealthy New York socialite, the daughter of
perfume importer Francis Rose Arnold and his wife Mary Martha Parks Arnold. As far as anyone knew she had a happy home life.
On the morning of Dec. 12, 1910, she left her home on the Upper East Side of Manhattan and told her mother that she was headed downtown to buy an evening dress. According to
The New York Times, when her mother asked if she could accompany her daughter, Dorothy said “No. When I find the gown I want, I will telephone you and you can come down and see it.” When she left the house, she had over $30 in her pocket. In today’s currency, that would be more than $750. On her way down 5th Avenue, she stopped at a grocery store on 59th Street to buy some chocolate, then at a bookstore on 27th Street where she bought a copy of
Engaged Girl Sketches, a humorous collection of short
romantic stories.
Around the time when she bought the book, she ran into a friend from college, Gladys King. The two talked about a party that they had both been invited to, the same party that Dorothy was buying a dress for. Gladys left to meet her mother for lunch and Dorothy was never seen again.
Francis Arnold was reluctant to gain publicity over his daughter's disappearance, and initially employed the help of private investigators. After those attempts were unsuccessful, the family filed a missing person report with the New York City Police Department in
January 1911. Various theories, sightings, and rumors regarding Arnold's disappearance circulated in the years and decades after she was last seen, but the circumstances surrounding her disappearance have never been resolved and her fate remains unknown.