The Oldest Confession — Richard Condon

An international art thief meets his match in this clever thriller that's “witty in style, dramatic in plot” from the author of The Manchurian Candidate (Kirkus Reviews).

There are only two people on earth who know that James Bourne is a criminal: his wife and his partner. Although he may be the most distinguished crook in Europe, Bourne has never been arrested. The thieves of London don't know his name, nor do the dons of Sicily or the police of Paris. A master thief, he's patient, careful, and utterly discreet -- but he's about to meet his match.
 
A handful of masterpieces adorn the walls of the palace belonging to the richest woman in Spain, and although she's a friend of Bourne's, he has never let a personal relationship get in the way of business. He plans to steal a few of the paintings, replacing them with impeccable forgeries made by his Parisian partner. But even the craftiest crook can be outsmarted, and this heist is about to turn deadly.