- Espionage: Leon was accused of spying for several foreign countries, including Germany, Russia, and Japan. He is said to have shared sensitive information about French military plans and troop movements.
- Fraud: Leon was also implicated in several financial fraud cases. He was accused of embezzling funds from a number of companies he worked for.
- Treason: Leon was eventually charged with treason and found guilty. He was executed in 1917.