Detaining war criminals as a well trained and disciplined military personnel VS weekend racist cop training. I take the military option lol.Sort of, I was trained to do a similar (ish) move in the military, and used it a couple times overseas. There are several VERY important differences though.
So the main reason you do it is to stop a person from bashing open their face, it isn't intended to really keep you safe, it is to keep the person being detained safe. If you have them on their front, with the legs fully extended and your foot preventing lateral movement, their neck is really the only movement they can have. If someone is REALLY angry or high, they will sometimes lash their head around furiously trying to bite you or something, and in the process smash their face open.
So what I was taught is to place the knee against the lower jaw (Gently, don't slam it down, just lower the knee slowly), and press the side of their face into the ground. NOT on the fleshy part of the neck, and NOT for more then 10-15 seconds at a time. Most of the time this immobilization stops the struggle, and you immediately release pressure.
There is a world of difference between that, which is a legitimate technique, and deliberately murdering someone by crushing his windpipe for 9 minutes. But at least in the military, the pressure on the neck (Jaw really) is something they teach, and it feels safe and appropriate when used correctly.