The canvas titled David with the Head of Goliath was painted a few months before Caravaggio died. His teenage David stands out against the dark background, holding Goliath's bloody head with an air full of melancholy. As you can see, the sword and shirt were painted with a quick and brusque brushstroke, which was typical of Caravaggio's later paintings.
FUN FACT: in David, Caravaggio painted himself in the jumbled head of the giant. His wild eyes and silent shout seem to be an omen of the painter's foreboding death.
