Homicidal Triad: Violence Indicator or Urban Myth?

Murderers don't usually go giving excuses for their crimes. I know Bundy blamed porn. But that was for a interview with a pastor. Serial killers don't go giving excuses unless they're trying for an insanity defense and then it to a psychologist. They usually know the excuses won't work although the psychologist might use their past as a reason for some mental incapacity. The psychologist isn't really looking for an "excuse" really but are asked to get a lighter charge or sentence. They usually blame everything  on childhood so are looking to shift the blame or make someone else share it, rightly or wrongly. 

Indicators are indications of homicidal tendencies. The abusive childhood doesn't determine the possible killer. No indicators might be present as the person might have a normal upbringing. It doesn't mean he wasn't the homicidal type. His nature is basically the same, only the lifetime "stressors" were different and maybe they didn't come in early life. 

I believe in taking sole responsibility but that doesn't mean you are solely responsible. Nobody exists in a vacuum. I wish some others would take sole responsibility and go away for life too, even if they aren't solely responsible.