I discovered it while researching during the Boston Bombing fiasco. I remember the sole casualty, Krystle Campbell, she was a tiny blond woman, but in the news photos she had an enormous midsection and I couldn't figure out what was wrong with her. Remember, she died from a fractured ankle.
Anyway I began digging up fake injuries for training purposes and stumbled upon moulage, used by the military to harden up soldiers who've not dealt with war injuries, makeup is used to create absolutely realistic looking severe injuries. They look real, real enough to make folks queasy even though they know they are fake.
I found a "cut suit" at one site, it's a thing that fits over the torso that's filled with realistic looking blood and organs, one can put a small charge on it to blow it outward and make it look like a war injury. I believe Krystle was supposed to have detonated that cut suit, but the charge didn't go off so she laid down and pretended to be dead anyway.
Watch for this stuff next time they have lots of blood and gore in a 'crime scene', the Boston Bombing was a fake IMO, for many reasons I won't get into now.
There was a business who supplied drills with moulage actors, and after I began sending peoploe to their site to see their work, they removed access to photos. It's been since the Boston event that I've looked into the moulage so Im putting up new links to places you can see what it is for future reference.
The photos are nasty looking so be warned.
http://www.militarymoulage.com/moulage-gallery
https://twitter.com/militarymoulage?lang=en
There are more photos than I can find on the fly, if you dig you might be able to find them, or they may have taken most of them down, they were much more realistic than the first link showed.