The investigation is a Préfecture embarrassment followed by an Italian authentication.
Steps below are what officials did after the wall was empty, not how the panel left.
Agencies
- Préfecture de police de Paris — Lead French investigation from 22 August 1911, including the Apollinaire dead end.
- Musée du Louvre — Victim institution; discovered the gap, later received the panel back.
- Uffizi Gallery / Giovanni Poggi — Authenticated the painting in Florence in December 1913.
- Florentine court and police — Arrested Peruggia, tried him and held the panel until the return to Paris.
What followed
- Record the empty wall
On 22 August 1911 the Louvre and police documented a missing Leonardo and alerted the press.
- Question staff and celebrities
Museum workers were examined. Apollinaire's arrest and Picasso's questioning showed the dragnet's celebrity bias.
- Circulate reproductions
Newspapers and police notices made the face a wanted image — useful for recognition, decisive for later fame.
- Receive the Florence offer
Geri's contact and Poggi's examination in late 1913 turned a rumour into an object in official hands.
- Arrest and authenticate
Peruggia was arrested. The panel was matched to the Louvre's picture.
- Return and convict
January 1914 brought the painting home. A Florence court convicted the thief on a short term.
Turning points
- The 22 August discovery — A Monday gap became a continental story before anyone had a suspect who would last.
- Clearing Apollinaire — The modernist panic ended without a painter in the dock for the portrait.
- Geri writes the Uffizi — A dealer's caution, not a Paris raid, recovered the object.
After the fact, Paris searched famous names and Florence recovered a panel. The file closed in 1914.
Public-record encyclopedia. Not legal advice. Not a how-to. Graphic detail is withheld. Wars belong in a separate atlas.