Before he died at the young age of 38 years,  Michelangelo Merisi da Caravaggio turned the art world upside down using "chiaroscuro," a lighting technique that created dramatic contrasts of light and darkness in his paintings. But that wasn't all that captivated Italian church goers who ogled his religious works. As models, Caravaggio used peasants, prostitutes, the poor and other citizens of questionable repute, scandalizing his contemporaries. He scandalized too, in the way he lived and died.  Join Ernest Granson as he interviews Andrew Graham-Dixon, journalist, author and art critic, whose biography, "Caravaggio - A Life Sacred and Profane", paints a picture of  a brilliant but troubled artist.