“Although rather methodical, he only paid attention to matters that directly concerned his thoughts of the moment. I feel sure that he had some definite reason for entering the closet, and therefore paid no attention to the door.
“If he had ever noticed it, his mind was so concerned with his specific errand that he forgot completely about the lock.”
Cardona looked in the closet again, and sniffed the smell of the fresh paint. He examined the bottom of the door, and saw that there was virtually no opening between it and the floor when the door was shut.
“Usually,” said the detective, “one should be able to obtain air in a closet like this. It is rather surprising that Sutton should have suffocated so easily.”
“How often has the closet been opened since it was painted?” questioned Biscayne, turning to Richard Sutton.
“I don’t recall that it was opened at all,” said the young man. “I may be wrong on that point. It may have been opened once or twice.”
“Then don’t forget the fresh paint,” said Biscayne to Cardona.
“Why?” asked the detective, in surprise.
“Fresh paint,” said the professor, “frequently produces carbon monoxide. That has been discovered recently.
“It was observed that men were taken sick while working in the freshly painted holds of ships. The cause was traced to the presence of carbon monoxide.”