True Crime Thoughts

Not to diminish in the least what happened to these two girls, but how can anyone seriously be surprised that a guy with numerous arrests and citations for violent behavior killed a couple of people? I mean, isn't a guy who once pointed a shotgun in the face of another person over a game system and who beat a stranger in the WalMart parking lot over some perceived slight that happened in the store precisely the sort of person you would expect to commit this type of crime?