That makes what happened to this extremely rare bird even more intriguing doesn't it? Did he die, just lose interest, (retire to the seaside perhaps) or was he incarcerated in an asylum and was just not listened to? The asylum would be Colney Hatch you would think, an interesting destination.
The reason I use Soto is not that he stabbed his victims dozens of times, but because he cut off their penises. Which I think most people would say shows something extra in the way of sadism. He had both rage and sadism. Fury and method.
I think you're on to something here. There can't be that many varieties of serial killers, although each was propelled by some particular "trigger". With Soto it was the black boys. Freud would have undoubtedly said that cutting off the penises was very significant. It might signify that Soto had felt emasculated, himself, by the penis of the original black man with whom his wife had cheated and which had produced the resented child. There was fury there of long standing that could only be temporarily abated by the homicide and the act of the cutting.
In the case of Jack, it was the women, the prostitutes. And plenty of rage--but what was behind it? A uterus is an organ of regeneration, too. One might say it represents the mother more than any other organ possibly could. To cut it out of a woman deliberately could certainly mean a deep-seated fury toward the mother, rather than any other female. There have been murderers of women who targeted the vagina, stuck stuff up there as if mocking it. This indicates a contempt for women, certainly, but does not speak to a hatred of the mother in the same way that an excision of the uterus would. This last act, for me, indicates knowledge that goes beyond what the average man would have. Cutting off a penis requires none. But actually excising a uterus is making a point only because one can--without possibly even realizing why one would want to. Or perhaps JTR did realize it and did it on purpose. After all, he could have contented himself by merely ripping up the victim's body as much as time allowed in a haphazard way or as the whim of the moment dictated. In the same way as a person defaces an advertising poster on a subway or somewhere that features a person's photographed face. Showing a lack of respect for the face, he or she defaces it in a cutesy kind of way. But there is no actual rage behind that if it is not done to an actual human visage. I think, when the Ripper did that, it was a combination of anger and trying to be "cute".