Nah, it's not that. I have been playing the CSI series since the very first games (the ones that weren't developed by TTG), and these models are from CSI: Deadly Intent, the previous game in the series.
It's that it's difficult to make a real person's 3D model look like the real person. But still, the 3DoM or the HE models were better, compare this guy:
To this guy (Hard Evidence/3 Dimensions of Murder):

And this guy (Fatal Conspiracy/Deadly Intent):
Over on YouTube people will scream, 'ololol bad graphix suk rainbow 6 vegas 3 ftw'
Appart from failing to distinguish the difference between "graphics" and "models" or "textures", they have obviously not played an adventure game lately.
Here are a few pics from some of the best lately (imo):
To sum up, the CSI:FC graphic engine (Sam and Max's engine) is very good for a adventure game, and most models (apart from the cast and the SWAT models) are very nice. Now, you should start worrying for the animation which looks a bit awkward in the trailer