of the other art they stole. >> the two, big rembrandts and the vamere, those three pieces account for 90% of let's call it $500 million, $400 million, whatever the mix, of the value. >> reporter: another big question, why did the thieves bother taken a golden finial that sat on top of a flag? at first, it seems they atechted to steal the flag itself. but it proved to be too difficult to take down. >> they wanted very badly to get that flag. that's always seemed to me to be the clue that is the most interesting. and i know the f.b.i. has spent a lot of time trying to figure that out. visiting, talking to, associations who are involved with napoleonic memorabilia to see was there a bounty for one of these banners? >> reporter: why did the thieves want that flag so badly?