I was fortunate enough to attend a briefing by a medical practitioner from the US who had looked in detail at the best way to neutralize a threat for the benefit of SWAT Team personnel having to deal with individuals high on drugs, specifically PCP. As part of the study he looked at ammunition types, shooting methods and areas of the body, which when hit would result in immediate shutdown of the nervous system. His report greatly influenced our range practices and subsequent design of targets to ensure muscle memory responses focused the individual on hitting the right areas. Basically in simple terms he encouraged one to focus on hitting the upper spinal column thus severing the brains ability to control any form of response - voluntary or involuntary.
A very useful reference is the manual written by Fairburn and Sykes as a direct result of their time in Shanghai (British Police detechment) in the 1930's, they studied at length the killing techniques of the Tongs / Triads and came up with a defensive / offensive system which greatly influenced the design of the Commando dagger and subsequent Commando 'killing' techniques adopted in WWII by the SOE and OSS.
A very useful reference is the manual written by Fairburn and Sykes as a direct result of their time in Shanghai (British Police detechment) in the 1930's, they studied at length the killing techniques of the Tongs / Triads and came up with a defensive / offensive system which greatly influenced the design of the Commando dagger and subsequent Commando 'killing' techniques adopted in WWII by the SOE and OSS.