'Looks' and 'Acts'?
Come on! Tells us why he looks and acts like a serial killer?
Hah! Watch the series “Criminal Minds” on TV. It’s all about profiling.
That's easy - he looks & acts like he's entirely separated from emotion, vacant. This is a tell-tale sign of a sociopath. The only time he shows any emotion is when he's defending himself and NEVER when speaking about the victim or their family, again a sign of severe narcissism almost always found in serial killers.
Lastly, he definitely has displayed a grandiose persona and sense of self, and people who know him say he can be incredibly charming. These are all signs of a sociopath, and are almost always found in one degree or another in most serial killers.
There's a great book called Without Conscience: The Disturbing World of the Psychopaths Among Us , that's available in paperback that really details the common traits found in modern serial killers. This kid fits most, perhaps all of them.