When Norton paused De Medici said aloud:
“But the thing in his hand. The false beard. He tore that off somebody.”
“Yes,” Norton answered, “off himself before he died. If you’ll look closely you’ll see there are evidences of gum mucilage on his chin.”
De Medici stood up slowly.
“The whole thing is insane, lieutenant,” he muttered. “Why should a man about to commit suicide disguise himself in a false beard?”
“You’ll see in a moment.” Norton waved him back to his chair. “I’ll give you my theory now and we’ll see if it will stand up under investigation. I purposely avoided asking the housekeeper a question. Now listen. Mr. Ballau desired to establish the fact that there was a stranger in the house. He put the beard on and showed himself thus disguised to his housekeeper. I’m sure we’ll find on asking her that there was a visitor here—a man with a black Vandyke. That she caught a brief glimpse of him. Call the Mayfield woman again, sergeant.”
De Medici waited in silence as the man at the door stepped out.
“He keeps looking at my fingers,” he whispered to himself. “And I touched the dagger. My finger-prints are on the hilt.”
He raised his voice.
“Have you searched for finger-prints on the dagger, lieutenant?”