Brady

You might be interested in this from John Garst, who has posted some info on 'John Henry' to this forum, in the archives the old-timey newsgroup:

Duncan and Brady is another 1890s St Louis crime. Brady was a white policeman, perhaps a vice squad cop (I'm not sure, but some versions of the song make him out that way). Harry Duncan was a well known black singer. There was a bar-room brawl into which Brady belatedly came, and he might have been plugged by Duncan. There is considerable question about this. Quite a few people thought that the owner of the bar fired the shot that killed Brady. Be that as it may, Duncan was executed for the crime.

Garst also references the following which may be worth your while tracking down:

John Russell David, 'Tragedy in Ragtime' 1970s
Dissertation about 'Frankie', 'Stagolee', and 'Duncan and Brady'.
Available from University Microfilms

The above comes from here: Click Here

--Stewie.