Was Jack caught by London underworld?

[ChrisGeorge]

Yes Jack was caught by the London underworld. The local bad boys caught the blaggard! Then they all had a go at the chappie sticking him with steely steel knives, just as in "Murder on the Orient Express" starring Kenneth Branagh as Dr. Tumblety.

[dixon9]

have to agree that although a plausible theory, just cannot see how it would have been kept a secret

[TomTomKent]

It's an interesting idea, but making it into a workable theory would be tricky, not least because if members of any kind of underworld were responsible, they would, by their nature, be making an effort to cover their tracks and hide the evidence of their murder.

This crops up regardless of if you think the Jewish community hid suspect X, the Masons hid Gull, or criminals made an unknown soul vanish.

If we hear about it, it will be through folk tradition. We will hear rumours that somebody tracked down the Ripper, and whispers that they were done away with. I would worry though, that such stories only choose to remember some aspects of events. For a starter, the story would be that the guy who was taken are of was Jack the Ripper. Whatever evidence there may, or may not, have been, then by golly, that was the guy. If there was any way of checking that, we would be exceptionally fortunate, but more likely, we would only ever be able to say "they got rid of somebody they believed to be the Ripper".

After all, the kind of people who tend to share stories, are the ones who are going to want to believe that version. Take, for example, how some people talk about certain gangsters from more recent times, as honourable men who kept law and order, and were only ever violent against other criminals who definitely deserved it. It may be part of the picture, and part of how they saw themselves, but from slightly different points of view, the picture is a lot less flattering.

That is not to say the idea is impossible, just... that even the best detective work will likely, unless blessed with exceptional luck of other evidence, fall a long way short of certainty (which, to be fair, is true of all suspects, given the nature of the limitations of evidence available so long after the fact).