Eugen Weidmann was born on February 5, 1908, in Frankfurt am Main, Germany. His family owned a business that exported goods. He grew up and attended school in Frankfurt. When World War I began, he was sent to live with his grandparents. This change in his living situation marked a difficult time in his life, and during this period, he began to steal.

As he grew older, Weidmann continued to get into trouble with the law. In his twenties, he was convicted of robbery and spent five years in jail in Saarbrücken. While in prison, he met two men, Roger Million and Jean Blanc. After they were all released, they decided to join together in criminal activities.

The three men planned to kidnap wealthy tourists in France and take their money. To do this, they rented a villa in Saint-Cloud, which is near Paris.

Eugen Weidmann and his partners planned to kidnap wealthy tourists in France. Their first attempt failed when the victim resisted too much. In July 1937, Weidmann met Jean De Koven, a 22-year-old dancer from New York. After a short time together, he killed her and buried her in the garden of his villa. They then demanded money from her relatives for her return.

On September 1, 1937, Weidmann hired a chauffeur named Joseph Couffy. He took him to a forest outside Tours and shot him in the neck before stealing his car and money. A few days later, on September 3, he murdered Janine Keller, a nurse, in a cave. He shot her and took her money and a diamond ring.

On October 16, Weidmann and his partner lured Roger LeBlond, a theatrical producer, under the pretense of a business deal. Weidmann shot him in the back of the head and stole his wallet. In late November, he killed Fritz Frommer, a fellow inmate he had previously met in jail, in the same way. Weidmann buried Frommer's body with De Koven's body in his villa.

Weidmann's final murder was of Raymond Lesobre, a real estate agent, on November 27. He shot Lesobre while they were looking at a house, taking another sum of money.

Weidmann was eventually arrested on December 8, 1937, after police tracked him down through a business card left at the scene of one of the murders. During his arrest, he shot at officers but was subdued. In custody, Weidmann confessed to all his murders. He expressed regret only for De Koven's death, describing her as gentle and unsuspecting.

In March 1939, Weidmann and his partners went through a widely publicized trial. He was sentenced to death, and on June 17, 1939, he was executed by guillotine in Versailles. His execution was the last public execution in France, followed by a ban on future public executions due to the disturbance it caused among the crowd.