Deadly Jigsaw Puzzle

My patient, Veronica Vail, was murdered in her Park Avenue apartment. Lt. John Franklin asks my help in finding the killer. We interview her husband Roland, his daughter by a former marriage who never liked Veronica, and Carlos de la Cuesta, a handsome, black-haired drag queen in love with Roland. Lt. Franklin hypothesizes that a stranger broke into the Vail apartment to steal a painting. Roland confirms that an expensive painting has disappeared. A maid named Lottie Lobell tells us that while looking out the window on the day of the murder, she saw a black-haired man run away from the building carrying a painting. He is found and brought in for questioning. Using purely psychological clues, I confront all the suspects with the truth. The killer collapses under my inquisition, and confesses.