Spanish Police and F.B.I. Get Their Men and Stolen Art
Spanish police and undercover FBI agent infiltrate Madrid hotel and, in sting operation, recover 10 of 17 masterwork paintings, valued at estimated $50 million, stolen in 2001 from mansion of billionaire construction magnate Esther Koplowitz Romero de Joseu; two suspects, Angel Flores and Juan Manuel Candela Sapiehia, identified as members of Eastern European criminal organization, are arrested and third, identified as former mansion security guard Luis Miguel del Mazo Lopez, surrenders; photos (M)

