my take on it all is that you have to be pretty messed up to begin with to go fight a "war" over seas thats not yours to begin with,,

any ways ,

if he killed overseas then yes he is a killer and probobly even a serial killer depending on the body count ,
in a sence while im no expert on the psychology of serial killers id say the killings started over seas with "unknown" victims and he continued back home with the same momentum , the fact that he killed someone he knew might be a sign that he was struggeling to cope with it all , kind a like a reversed introvert / extrovert expression of one self , his way of asking for help went so over board the only way he could do it was to show it ,

anyways , you dont send kids to do a mans work ,

Its probably a combination of genes as well as hostile environment. Like a perfect storm of situations. He might have had ideas before he went into the mil but those changed to actions after.

EDIT: yea what above poster said...

If I may give my 2 cents, I am a mental health professional. This fellow probably has Antisocial Personality Disorder. In the old days, they called it "psychopath" or "sociopath". Because of this, he was probably drawn to that type of profession (soldier, cop, mercenary, etc.) because it's an outlet for his need to dominate or destroy for a sense of power. Even if he was "normal" and went in to the service, then was traumatized in battle - if he were not APD he would most likely be suicidal or have problems secondary to abuse of drugs/alcohol.

It's important to note that not all APD's are serial killers. In fact, only a small percentage of them kill at all. Most are just what the rest of us see as jerks. They typically have no empathy for others, nor interest in the needs or rights of others.

Whether APD is something you're born with or created by an abusive childhood is a matter of ongoing debate. I personally think it's a combination of both. It is not treatable - no amount of counseling or medications can change it.

Originally posted by Rockerchic4God

It's important to note that not all APD's are serial killers. In fact, only a small percentage of them kill at all. Most are just what the rest of us see as jerks. They typically have no empathy for others, nor interest in the needs or rights of others.

Lol, this sounds like just about every person in the US these days. People have to be sociopaths and narcissists to get ahead in the rat race. Or even survive