I did an internship with these guys a couple years ago, and one of the teams was already working on the problem. Ekman's ideas were specifically brought up as a basic idea of what they were doing, but expanded beyond just microexpressions and the like. Some other things they were looking at included pore-dilation, and thermal imaging.

It wasn't my team, so I don't remember too many details, but I remember a problem being that they had to have the subjects immobile in one place, and surrounded by an array of very expensive cameras and sensors.

If you could design a system where you could set up enough sensors to look at everyone in a room, despite the fact that they were moving around, etc, and be able to pick out warning signs for violence (one of their most desired use cases), you'd be in business.

They were sponsored by DARPA or AFRL, but the work was public, so might be able to find some info by browsing around. Also, if they were doing it, I would guess that other colleges were too.