A affluent socialite strolled out into Fifth Avenue's sunny streets on December 12, 1910, only to subsequently vanish and never be seen again. About midday, Dorothy Arnold, the affluent cosmetics and perfume manufacturer's daughter, departed from her Fifth Avenue home. She had a brief conversation with a friend she ran into outside of a bookstore at 2 p.m. after running a few errands; that was the last anyone saw of her.
The police and her family spent many hours tracking her final movements on the day before she vanished, and newspapers all over the country were in a frenzy. Newspapers chronicled the investigation as well as the seemingly never-ending stream of hazy leads and tips. And yet, despite the intense media attention the case received and the protracted inquiry that lasted for years, no firm theory was ever developed to explain why she vanished.
A few hours later, when she failed to show up for supper, Dorothy's disappearance was discovered. The family withheld her absence from the police and chose to hire their own investigator, albeit she was the daughter of a wealthy family, so they hoped to avoid negative publicity. Yet after six weeks, hopeless and desperate, they at last turned to the police for assistance.
Her actions preceding her disappearance were thoroughly tracked down and examined during the ensuing police inquiry. Many possible suitors were present in Dorothy Arnold's active social life, and many of them were detained for questioning in vain. Given the social standing of the Arnold family, the case attracted attention on a global scale, and for years, leads poured in from all over the world. Yet none of them had any real significance.
A store owner stated that he saw Dorothy Arnold looking for a steamboat fare and purchasing men's clothing in the early days of 1911. She was reportedly seen in Italy, Chile, and numerous other foreign and domestic cities, but none of these sightings turned out to be true.
The assertion made by a prisoner in Rhode Island that he had been recruited to assist in the December 1910 burial of a wealthy woman in a cellar may have been one of the more plausible leads, though it never materialised. Yet after years of hoping beyond hope, her father finally came to believe that she had been abducted and murdered, a conviction he clung to right up until his passing.
Arnold's family attorney publicly announced his own theory following the passing of both of Arnold's parents: Dorothy killed herself as a result of her failure as a would-be author. The absence of a body, however, seriously undermines both that theory and the others.
Although the average New Yorker is unaware of this tale, it was widely publicised and reported at the time of the investigation, from small-town papers to big metro editions. It was the "truly great search of the period," according to the Pittsburgh Press, and it significantly influenced contemporary newspaper police coverage.