Does murder run in the family?

Is it possible that a murderer could have inherited his thirst for blood from his family? For Diamond Blair of Baltimore, Maryland, that would seem to be the case. Blair, 33, recently implicated in the June killing of a robbery victim, is the son of a convicted murderer, the brother of an alleged murderer, and the nephew of one of the cities worst known serial killers, a man who killed six women in 2004. For Blair, this charge is only the most recent in a string of crimes which have become increasingly violent since his first arrest at age 6 for stealing.

Cases like these tend to raise questions about nature versus nurture. Does the Blair family suffer from a genetic disorder that makes them predisposed to violence? Or are their homicidal tendencies the result of their upbringing and the moral decay of their environment? If you have criminals in your family tree, does it make you more likely to go bad? We know that vices like alcoholism are passed down from generation to generation. Is murder?

What do you think? Nature or nurture? Fate or choice?