“Yes, sir.” She grasped eagerly at the suggestion.

“The person would have had to know Mr. Benson pretty well to tap on the window instead of ringing the bell. Don’t you agree with me, Mrs. Platz?”

“Yes—sir.” Her tone was doubtful: evidently the point was a little beyond her.

“If a stranger had tapped on the window would Mr. Benson have admitted him without his toupee?”

“Oh, no—he wouldn’t have let a stranger in.”

“You are sure the bell didn’t ring that night?”

“Positive, sir.” The answer was very emphatic.

“Is there a light on the front steps?”

“No, sir.”

“If Mr. Benson had looked out of the window to see who was tapping, could he have recognized the person at night?”