Hmm... I know this is bit of an old piece, but what did you intend with this? Was it a product to be sold?
Because if it was the overall style is nice, but I do see a few problems with brushwork that could have been resolved to make it better ^^ If you would mind hearing of course ^^
For one, the brushwork, while giving a gritty film noir look to the scene, happens to have a few technical issues, where you can see the lines on the artworks shades. This of course as you explained may be due to you using Bristol, where the ink doesnt blur these lines by absorption, but it can also stem from using too much pressure on the pen. ^^ The only true shades that should show up in a piece that often help are the blacker lines, which can be imagined as the mans pants, or maybe the inside of the police window. ^^
The thing also has a sort of lack of detail that while staring at it from a distance gvies it a very harsh and gritty atmosphere of tension, makes it look rather empty when examining it close to ^^
However that said, this piece certainly does show some skill