After time in the British Military---the SBS---I was seconded to a smaller group where I did individual assignments. That means that I killed people, as a government-directed assassin---people inimical to the country's best interests.
But I found myself becoming callous and resigned my commission.
I came to America, started a business engineering components for race engines---primarily for the Roush NASCAR operation, and found myself bored due to inaction.
I've found plenty to occupy myself, though, in Detroit, the most violent metro area in the country. Those who might be aggressive find themselves to be the endangered ones.