Trois balles dans la peau

Open and shut case: Maxime Dartois, the painter, is found dead in his penthouse with three bullets in his body, but the pistol that killed him is still being held by the (fainted) young lady by his side. A detective will find a few odd notes, and the plot thickens when plenty of people are interviewed, and more than one could have the will, and the opportunity, to be the killer, and it is not clear what the relationship of the girl was with the deceased.