In 1913, Milwaukee housewife Walburga “Dolly” Oesterreich made a decision that would lead to one of the most bizarre criminal cases in American history. Bored with her marriage to wealthy textile manufacturer Fred Oesterreich, the 33-year-old housewife began an affair with Otto Sanhuber, a 17-year-old sewing machine repairman who worked for her husband.
When neighbors became suspicious of the young man’s visits, Dolly proposed a radical solution. She moved Otto into the unfinished attic of her home, directly above the bedroom she shared with her husband. For the next decade, Otto lived as a “sex slave” and a ghost, existing only for Dolly while remaining completely invisible to her husband.
A Secret Lodger
Otto Sanhuber’s life in the attic was grim. He had a cot, a lamp, and piles of books to keep him occupied during the long days of silence. He could only move around freely when Fred was at work. At night, he lay still in the crawlspace, listening to the couple below.
Despite the harsh conditions, Otto did not leave. He became dependent on Dolly for food, affection, and human contact. When Fred decided to move the family to Los Angeles in 1918, Dolly agreed on one condition: the new house had to have an attic. She sent Otto ahead to California to settle into the new crawlspace before she and Fred even arrived.
A Staged Burglary
On August 22, 1922, the arrangement shattered. Otto, listening from his hiding spot, heard a violent argument erupt between Fred and Dolly. Believing Dolly was in danger, he burst from the attic brandishing two .25 caliber pistols. In the ensuing struggle, Otto shot Fred three times, killing him instantly.
The lovers quickly staged the scene to look like a botched robbery. Otto took Fred’s expensive diamond watch and locked Dolly in a closet from the outside, tossing the key into the garden before retreating into the ceiling. When police arrived, they found a hysterical Dolly trapped in the closet, reinforcing her story of an intruder.
The Ghost Revealed
Incredibly, Otto remained in the attic even after Fred’s death. He continued to live in the crawlspace for another eight years while Dolly took on new lovers. The scheme finally unraveled when Dolly gave Fred’s distinct diamond watch—the one supposedly stolen by the burglar—to a new boyfriend, Herman Shapiro. Suspicious, Shapiro eventually discovered the “vagabond half-brother” living in the ceiling.
He went to the police, exposing the decade-long deception. The press dubbed Otto “The Batman” due to his cave-like existence. Although a jury convicted Otto of manslaughter in 1930, the statute of limitations had expired, and he walked free. Dolly’s trial ended in a hung jury, leaving the “Batman” of the attic as a strange footnote in criminal history.
In 1913, Dolly Oesterreich took a lover, but she didn't just hide the affair, she hid the man.
For ten years, Otto Sanhuber lived in the attic above the bedroom she shared with her husband.
He was a "sex slave" ghost who only came out when the husband left for work…🧵👇 pic.twitter.com/XhFvzDMeIb
— Fascinating True Stories (@FascinatingTrue) December 25, 2025