My understanding about all these murders is that as soon as a rapper starts making money, the gangs (the street mafia) move in on them and demand protection money. If they don't pay, they get shot. When you grow up on the street in a bad neighborhood, you get to know people who you really do not want to know. And when you start making money, they all come calling.
If I was a 'rapper', god forbid, I would have an army of bodyguards with me all the time. It does no good to get rich and famous if you're dead.