http://www.slate.com/articles/news_and_politics/crime/2015/08/isabella_stewart_gardner_museum_video_why_is_stolen_art_so_hard_to_find.html

Twenty-five years ago, two thieves dressed as police officers bluffed their way into Boston’s Isabella Stewart Gardner Museum and made away with $500 million of artwork by Rembrandt, Vermeer, Degas, and others. The thieves didn’t cover their faces, and they apparently didn’t know much about what they were stealing: They roughly cut the paintings from their frames and left more valuable works hanging on the walls. Despite the thieves’ apparent inexpertise and the ensuing media attention, no suspects were ever arrested and the art was never recovered. Authorities believe the robbers were regional gangsters, but nobody really knows where the art has been stashed, or if it’s even still intact. The Gardner robbery is the biggest and most frustrating art heist in American history—and it’s as cold as cold cases come.