Moishe the Ripper?
That's right, 120 years after the grisly murders — between bites of bagel and in-depth research on Corey Haim — we at JONJ have solved this historic crime. For you see, if you look at the angle of the cuts on the second victim, it becomes increasingly clear that...
Oh who are we kidding? Jack the Ripper's true identity will forever be lost to history along with the recipe for Greek Fire and Steve Guttenberg's popularity. Discussing his (or hers. Take that traditional expectations!) potential Judaism is like discussing the Judaism of a shadow. We might as well argue whether or not G-d is Jewish. Wait, we already did that? Oh well.
In any case — before all this rambling leads us down a dark, dingy London alley — a few of the Ripper suspects were Jews: Kosminski the hairdresser, Pizer the bootmaker, and a few others. None of them sound particularly likely. For the most part — excepting Kosminski who was clearly insane — the only profile these poor landsman fit was that of a foreigner with an unpopular religion: an easy target in late 1800s England.
But all of this is just so much filler, really. Here's the short version. No one knows who Jack the Ripper was. No one will know. So we can say for certain that Jack the Ripper wasn't Jewish because, well, good luck proving us wrong. Besides, we know the real secret. Jack the Ripper was none other than... Corey Haim!
Wait, no, that's not right...
(Editor's update, September 7, 2014: Yes, we are aware of recent DNA evidence. Please click on the Kosminski link below.)