The outside public may think that the identity of that later miscreant, "Jack the Ripper," was never revealed. So far as absolute knowledge goes, this is undoubtedly true. But the police, after the last murder, had brought their investigations to the point of strongly suspecting several persons, all of them known to be homicidal lunatics, and against three of these they held very plausible and reasonable grounds of suspicion. Concerning two of them the case was weak, although it was based on certain suggestive facts. One was a Polish Jew, a known lunatic, who was at large in the district of Whitechapel at the time of the murder, and who, having developed homicidal tendencies, was afterwards confined in an asylum. This man was said to resemble the murderer by the one person who got a glimpse of him--the police-constable in Mitre Court. The second possible criminal was a Russian doctor, also insane, who had been a convict in both England and Siberia. This man was in the habit of carrying about surgical knives and instruments in his pockets; his antecedents were of the very worst, and at the time of the Whitechapel murders he was in hiding, or, at least, his whereabouts was never exactly known. The third person was of the same type, but the suspicion in his case was stronger, and there was every reason to believe that his own friends entertained grave doubts about him. He also was a doctor in the prime of life, was believed to be insane or on the borderland of insanity, and he disappeared immediately after the last murder, that in Miller's Court, on the 9th of November, 1888. On the last day of that year, seven weeks later, his body was found floating in the Thames, and was said to have been in the water a month. The theory in this case was that after his last exploit, which was the most fiendish of all, his brain entirely gave way, and he became furiously insane and committed suicide. It is at least a strong presumption that "Jack the Ripper" died or was put under restraint after the Miller's Court affair, which ended this series of crimes. It would be interesting to know whether in this third case the man was left-handed or ambidextrous, both suggestions having been advanced by medical experts after viewing the victims. It is true that other doctors disagreed on this point, which may be said to add another to the many instances in which medical evidence has been conflicting, not to say confusing.