I created a few concept art illustrations to try and represent the detective’s room. Only my last one has addressed the issue of chiaroscuro lighting. I’m sure there are better ways to do it, but the idea of simply representing it with carefully placed areas of block black paint or paper appeals to me. The Hollywood movies that use these lighting techniques emphasise these visual contrasts for dramatic effect and they do it using things like reflectors and careful stage lighting. It seems somewhat appropriate to manufacture the desired outcome as well.
And this method means that the room doesn’t actually have to be badly lit, which could result in personal injury or damaged property and we don’t want either of those do we?