After informing his superiors about what had occurred, Ronde, with a group of his men, entered Redl's hotel room and found Redl writing a note. Redl cordially welcome them in, telling them that he knew why they were there and that he was writing farewell letters. Asked the extent of his treachery, he referred Ronde to the Prague mansion, where he said all answers lay. Redl asked to borrow a revolver and five hours stood naked in front of a mirror surrounded by lights and shot himself in the head. Redl's last note stated "Levity and passion have destroyed me. Pray for me. I pay with my life for my sins. Alfred…."

The Austrian government attempted to keep quiet Redl deeds, but a hotel worker leaked information about the suicide, as did a locksmith brought in to help authorities break into Redl's house.

An examination of the Prague mansion revealed the level of income he was receiving from the Russians as well as the depth of his disloyalty. Thousand of secret documents were found as well as list of agents and contacts. Most significant was the discovery that information provided by Redl had been passed to Austria's biggest enemy, Serbia. Included in this was Austrian's plan in case of a war with Serbia. After a Serbian anarchist assassinated Archduke Franz Ferdinand, Austria did go to war against Serbia, but was repelled by the Serbian who knew their plans. Thus much of Europe and the United States was drawn into World War I.