Suffice to say genuine suspects are far fewer than the prolific authors of the genre would have us believe. In fact, to reduce them to only those with a genuine claim having been nominated by contemporary police officers, we are left with a mere four. They are;
- Kosminski, a poor Polish Jew resident in Whitechapel;
- Montague John Druitt, a 31 year old barrister and school teacher who committed suicide in December 1888;
- Michael Ostrog, a Russian-born multi-pseudonymous thief and confidence trickster, believed to be 55 years old in 1888, and detained in asylums on several occasions;
- Dr Francis J. Tumblety, 56 Years old, an American 'quack' doctor, who was arrested in November 1888 for offences of gross indecency, and fled the country later the same month, having obtained bail at a very high price.
The first three of these suspects were nominated by Sir Melville Macnaghten, who joined the Metropolitan Police as Assistant Chief Constable, second in command of the Criminal Investigation Deptment (C.I.D.) at Scotland Yard in June 1889. They were named in a report dated 23 February 1894, although there is no evidence of contemporary police suspicion against the three at the time of the murders. Indeed, Macnaghten's report contains several odd factual errors.
Kosminski was certainly favoured by the head of the C.I.D. Dr. Robert Anderson, and the officer in charge of the case, Chief Inspector Donald Swanson. Druitt appears to have been Macnaghten's preferred candidate, whilst the fact that Ostrog was arrested and incarcerated before the report was compiled leaves the historian puzzling why he was included as a viable suspect in the first place.
The fourth suspect, Tumblety, was stated to have been "amongst the suspects" at the time of the murders and "to my mind a very likely one," by the ex-head of the Special Branch at Scotland Yard in 1888, ex-Detective Chief lspector John George Littlechild. He confided his thoughts in a letter dated 23 September, 1913, to the criminological journalist and author George R Sims.
For a list of viable suspects they have not inspired any uniform confidence in the minds of those well-versed in the case. Indeed, arguments can be made against all of them being the culprit, and no hard evidence exists against any of them. What is obvious is the fact that the police were at no stage in a position to prove a case against anyone, and it is highly unlikely a positive case will ever be proved. If the police were in this position in 1888-1891, then what hope for the enthusiastic modern investigator?