What this man did is off the scale wicked.
The causes of violence are complex, we all know that. There's evidence that most UK prisoners have some sort of addiction issue, lots of them (both male and female) will have had violent/dysfunctional upbringings, lots have undiagnosed learning difficulties and/or ADH so didn't do well at school and have struggled to get jobs, no stable family life, genetic influences might be at play in psychopathy, a great many have had head injuries which can cause brain damage - etc etc etc.
But putting all of that to one side, the fact remains that men are far more likely to be violent than women and almost all family annihilators, terrorists, serial killers are male. Who knows if it's the testosterone or the socialisation or just the knowledge that they can overpower physically weaker people like women, children, the elderly? No idea what we can do about it, but it should be a priority for governments. Not holding my breath on that one, though.