Should I date someone who has killed people while in the military?

I recently met a nice guy who has killed people while in the military. I asked him about it and he said it was always out of duty or because the people he killed were doing something morally wrong, like throwing rocks at a women and beating her. He said he never killed a women or a child, and that he felt remorse but at the time he had to do what he had to do, or he felt compelled to kill for morale reasons because the people he killed were doing some immoral. I am looking for something long term with a guy, he seems very sweet. He went with me to church and he enjoyed it. Could this person make a good husband and father? Or is it that once you kill someone you turn into a mean person or have other mental and emotional problems that cannot be resolved?