I've encountered a glitch in the Steel Mill that wouldn't let me progress any further. Minor spoilers ahead.
This is at the point where Copperhead poisons you. I'm supposed to scan the crime scene, but whenever I get to this part (2:09): http://www.youtube.com/watch?feature=player_detailpage&v=huh-Pwl9hxU#t=129,
it doesn't work properly. The "reconstructing the crime scene" bar never appears and I'm just forced out of the detective mode every time I try to do this.
I googled around and found a few similar cases, always involving the crime scene reconstruction feature of the detective mode. Peculiarly enough, this issue does not seem to be PC-exclusive as someone apparently encountered it on the 360.
I very much doubt that someone on these forums would be able to come up with a fix since all of those past issues were never resolved, but you're welcome to try.
EDIT: The bug somehow disappeared after about a sixth restart of the game (note that about two weeks have passed between the first and the last ones). I'm not exactly sure why or how this happened, but you could try doing the same thing if you have also encountered this issue.