Get your library to get get you this article:
Preeti Nijhar, 'Imperial Violence: the Ethnic as a Component of the Criminal Class in Victorian England' in
Journal Liverpool Law Review (Publisher Springer Netherlands) Issue Volume 27, Number 3 / December, 2006 (available
online)
This Old Bailey page looks specifically at members of the Black community,
and Michael Herbert Fisher has analysed those cases for you here.
Otherwse, there's very little on the web - just snippets that you would have to follow up, such as
here.
If I were you, I would try to contact some expert.
Try emailing
Preeti Nijhar (at the University of Bangor): s.k.nijhar@bangor.ac.uk
or
Humayun Ansarior
Michael Herbert Fisherand ask them.
Be polite, and be aware that some of academics can be extremely nasty people, but if anyone can help you, they will be able to. Some academics are so delighted when they find someone interested in their subject, that they are effusively helpful!