Despite the small army of professional and amateur detectives at work on the case and the untiring labors of the missing man's friends, it was an accident rather than a clue that brought about the first important development of this sensational tragedy. On Thursday morning, May 9th, five days after the physician had disappeared as completely as though the ground had opened and swallowed him up, a stable owner named Foley, having barns on Fifteenth Street near Centre Avenue, entered the Twelfth Street Police Court while the hearing of a case was in progress, and informed Lieutenant Beck that a young man had been trying to sell him a horse and wagon and that he had agreed to purchase the rig for $10, in order that he might detain the supposed horse-thief until the police could be notified. Two officers, O'Malley and Halle, were at once sent to the barn. The man, upon being placed under arrest, at once fainted. Upon regaining consciousness, he was started for the station. His peculiar agitation was noticed by the officers, and one of them, in joking about a horse-thief having such a nervous temperament, made a slight remark in which he mentioned the name of Dr. Cronin. The prisoner evinced a strong tendency to faint again, and gasped: "I'll tell you all when I get to the station." The officers laughed. Their dull comprehensions failed to connect the remark with the trunk mystery. When the station was reached, however, and the attention of Lieutenant Beck had been called to what the man had said, he at once jumped to the conclusion that the horse was the one attached to the wagon that had hauled the mysterious trunk. He ordered the man into his private office and at once began to put him in what is known in police parlance as "the sweat box," or in other words, to put him through a rapid course of questioning. At first the man--a mild mannered young fellow, attired in clothes of cheap material, with bad complexion, square features, heavy jaws, and a pronounced squint in one eye--gave his name as Frank J. Black, although he afterwards admitted that it was Woodruff. He was, he said, 26 years of age, a Canadian by birth, and a railroad laborer by occupation. "I want to make a confession," he remarked, after the preliminaries had been completed. He was warned that it would have to be entirely voluntary, and that no immunity could be promised. To this understanding he gave his assent, and Sergeant Cosgrove, having been called in as a witness, the prisoner commenced his story: