I found the account below interesting on a number of points:
1) It includes an early attempt at geographical profiling, concluding that the likely residence of the killer was in Goulston Street
2) It extends the cattle boat theory to specify that the killer may have been a Jewish butcher working on these boats
3) It mentions another letter to our old friend Albert Backert, addressed from the Eastern Hotel, Poplar
18 July 1889
SPECULATION AS TO THE MURDERER AND HIS METHODS
The Press Association says:-
While there is a general belief amongst a considerable portion of the local police that the murderer has not left the neighbourhood since the murder and mutilation of Mary Jane Kelly on the 9th November last, but that he has been living within a short distance of Commercial Street Police Station, there is a theory, which was mooted on the occasion of the last murder, that has a much more substantial foundation. The former belief receives confirmation in the fact that the whole series of murders, commencing with that about the August Bank holiday last year, have been perpetrated within a radius of Goulston Street, Spitalfields. Furthermore, it is pointed out that all the victims have been residents within the same area, particularly near Goulston Street, the centre of the radius. There is at least one point certain, and that is that the criminal knows considerably more of the working of the police force in the district than the police know of the criminal's modus operandi, and this fact, which has long been recognised by the authorities, has led them to originate a system of short beat duty, by which two officers traverse the same beat in opposite directions. It was thought that this would "fog" any outsider who had but an elementary knowledge of police duty, but, like all the efforts of the police in this direction, it has hopelessly failed. The second hypothesis is not only more feasible, but it has been taken up by the police authorities as a foundation upon which to base future investigation. It will be remembered that in November last it was suggested the murderer came from one of the Continental ports on board a cattle boat, and after perpetrating a murder returned by the same vessel. The police have now reason to believe that this idea, which was ridiculed at the time, that the murderer is a foreign Jew butcher has some foundation, and, accordingly, instructions were issued to the Detective Department yesterday. It has been noticed that the crimes have invariably been committed about 1 a.m. on a Thursday or Friday, and this has led to a growing suspicion in connection with the boats referred to, which arrive on Tuesdays and Thursdays and Wednesdays and Fridays, returning on the following day to their respective ports. The butchers employed on these boats land for the night and usually stay in the neighbourhood of Whitechapel. Blood on clothes of such a man would not be regarded with suspicion, and it is stated that the clean cuts inflicted on the victims are peculiar to this class of men's mode of killing cattle, while the doctors' testimony has proved that the murderer has a rough knowledge of anatomy, such as these men would possess. It has been ascertained that some cattle boats arrived on Tuesday at the docks, and sailed again yesterday, and this, taken in conjunction with the above theory and Tuesday night's murder, has led the authorities to issue orders to the East End and Thames police to watch all vessels about to leave the Thames, specially cattle boats which trade between London, Oporto, and other Spanish ports, and also American ports, and request cattlemen to give an account of themselves on the night of Tuesday or the morning of Wednesday. Detective Inspector Regan, Thames Division, with a large staff of detective officers, are in consequence busily engaged in carrying into effect the order, and all passenger vessels are boarded by officers and passengers carefully scrutinised. The Press Association learns that as corroboration of the above theory, and justifying the action of the Thames police, a letter was received a few days ago by Mr Albert Backert, 13 Newnham Street, Whitechapel, as chairman of the Vigilance Committee, from "Jack Ripper," announcing his intention of recommencing operations about the middle of July. It commenced "Eastern Hotel, Pop_," and then thickly penning out the words. Since yesterday morning's murder inquiries have revealed the fact that there an Eastern Hotel in East India Dock Road, Poplar, used as a rendezvous by seamen. It is within a stone's throw of the docks. It is thought probable that the murderer may have been on a voyage during the interval between the Miller's Court murder and the one perpetrated yesterday morning.