“The burglary motive?” asked Biscayne.
“YES,” announced Cardona. “Some one wanted to get something out of that place. The grating, at the window, could be easily removed. Perhaps the murderer was preparing to remove it when Harshaw surprised him.
“Now, assume that the motive was burglary. Just as surely as the man killed Harshaw, just as surely he did not enter the apartment. Therefore, he didn’t get what he was after.”
“Considering burglary as a motive,” said Biscayne, taking advantage of Cardona’s pause, “the fact that the intended burglar did not enter, shows probably that he did not contemplate murder as well as burglary.
“He had to kill Harshaw; and when he did, he wanted to get away as quickly as possible.”
“Yes,” agreed Cardona, “and he still wants whatever he didn’t get. Therefore — when he recovers his nerve — he will be back again.”
Biscayne nodded thoughtfully, and his heavy brow became furrowed. His eyes shone through his large-rimmed spectacles. He saw what Cardona was planning.
Commissioner Weston’s brain was working slowly. His face still showed perplexity when Cardona resumed his speech.
“We’re going to lay a trap for that fellow,” he said. “It will be baited tonight. I have said very little about the ladder from the room beneath, because a search of that room gave no tangible clew.
“The Redan Hotel is an easy place to enter. I have let it get about, that we are locking up Harshaw’s apartment, and that there will be no police on duty there.