Following Stéphane Breitwieser’s capture at the Wagner Museum in November 2001, Anne-Catherine avoided arrest. In May 2002, detective Alexandre Von der Mühll questioned her in France; she denied helping any artworks vanish. That same month, French police interrogated Mireille Stengel, who admitted a solitary “crisis” but left the timeline unclear. Even by 2005, Breitwieser could only piece together fragments from his mother and investigators.

Breitwieser believes Anne-Catherine drove straight to Stengel’s home and told her of the arrest. Seeing the attic’s vast trove and fearing exposure as an accessory, Stengel erupted. She swept objects from furniture, yanked down numerous paintings, filled seven or eight garbage bags and boxes with silver, ceramics, ivory, and a copper painting, and began clearing the space.

That night, Stengel drove to a secluded bridge on the Rhône-Rhine Canal and threw the contents into the water, then returned for a second load, including more silver, coppers, a large tapestry, and a 150‑pound Virgin Mary statue. Breitwieser suspects her new partner, painter Jean-Pierre Fritsch, helped; police later recovered ten stolen silver pieces from Fritsch’s pond, though he denied involvement.

Stengel abandoned the Virgin at a country church, where it was recovered and reinstalled. The tapestry was tossed in a roadside ditch, mistaken for a rug, and later identified after canal finds. Three copper paintings wrapped in red Air France blankets were left in a forest; a woodsman used them to patch a henhouse roof before news reports prompted their recovery. Meanwhile, Stengel removed hooks, spackled, repainted, and erased traces in the attic.

Finally, Stengel loaded the remaining oil paintings on wood—more than sixty—drove them “to the forest,” piled them in a clearing, and set them ablaze, likely without needing accelerant. Breitwieser wanted to believe she acted to protect him, but Stengel told police she meant to punish him. The fire consumed the collection, leaving little but ash.