Graeme −> Language −> Ever wonder? −> Assassins 

John Wilkes Booth;
Lee Harvey Oswald

Whenever you hear a person identified by three names, what immediately springs to mind?  That's right.  He's an assassin.  Why should it be the case that assassins are so often known by three names?  Is it the trauma of being forced to recite all three names all throughout life that so weighs upon a person that it drives him to become an assassin?

I have a simpler explanation.

When a person is accused of a heinous crime, the authorities who release his name want to ensure that very few innocent people will be accidentally confused with the bad guy, so they release the full name of the alleged assassin.  That way, John Randolph Booth or Lee George Oswald won't be accidentally run out of town by an angry, but misguided, mob.