Bod said:
What are the classic indicators that someone is on such drugs?
I've known a few speed freaks, and it seemed they stared like they were insane. Big eyes. Jerky movement. But is this enough?
If the prosecution asks me in front of a judge and jury why I belted someone in the throat, I'd like to be sure that I was not jumping to conclusions when I say 'I thought he was on drugs because of x, y and z'.
I would think that the continuous and lethal bezerker attack behavior would be pretty good evidence that you were justified. If the person can be found to be on drugs or a regular drug user (and you are the cleaner boy scout of the two of you before, during and after the actual incident) then it only makes his case worse and yours easier to justify.
In the moment (meaning before, during and after the use of force), if someone poses a reasonable threat it doesn't matter if I have assessed that they are drug altered, mood altered, sleep altered.... I just have to be able to explain/defend/justify my use of force was based on a reasonable indication of danger (consult your local LEO's/County Court attorneys for what that means in your area). If you start throwing around statements like "I knew he was a danger because he was on drugs", and it turns out to be inaccurate - then there is a hole in your justification that legal beagles can tear apart (not to mention the undermining of your character/credibility with questions like "So, how do you know so much about illegal drug use?", "Are you trained in some medical capacity to diagnose drug use, or just a person who watches too much crime drama on TV?").
Simplest thing is to just report action and behavior: "When I tried to walk away, he followed me and grabbed me", "He kept staring at me saying he was going to kick my a**", "He was screaming like a monkey and tearing his clothes off just before he picked up the brick and tried to beat me on the head with it"...or what ever. LEO's know this communication technique in relation to DWI and Blood/Ox testing equiptment and such. Language is powerful stuff.
It is good that people are looking at the full spectrum of what using force in our culture can mean though. When training for self defense I try and consider what I have to do in three major 'arenas' of self defense 'battle':
1. Inside myself (emotional/physiological responses to stress)
2. The threat (person(S) posing a danger, natural disaster, ....)
3. Legal system/Institutions (justifying/defending my use of force/dealing with probate or insurance companies... all the FUN stuff

)