So when did it all begin?

[TomTomKent]

No, I am not asking who the first victim was, but rather when the idea of a threat was first apparent. IIRC the idea that Leather Apron had been harassing women was established before the canonical five victims, so the gossip could suggest he was assumed to be the fiend. Which makes me wonder, when exactly did the rumours of Leather Apron, or some other violent individual first emerge?