In 2011, investigators searched a home in San Diego. The man who lived there claimed to have the slippers. He had the wrong pair.
In 2013, the museum hired a private investigation firm. In 2015, divers went down into the Tioga Mine Pit Lake, a flooded mine pit 225 feet deep. They found nothing.
Police had first offered a $250,000 reward. In 2015, an anonymous donor offered $1 million. That offer ran out, unclaimed, on the tenth anniversary of the theft.