Going by what I've seen in Trinidad (where there is a very high crime rate, and frequent violent kidnappings for ransom which sometimes end in murder), I think poverty is generally the primary engine of crime....and specially extreme poverty which exists alongside the presence of an obviously wealthy elite. It is the social disparities between rich and poor as much as the poverty that will drive the crime rate up.

Another thing that can exacerbate the situation is a corrupt government and police force. If the police themselves are subject to bribes and corruption on every level, as is the case in Trinidad and has always been the case in much of Latin America, then it can only get worse.

Another thing that can drive crime up is a poor educational system.

Another thing is the illegal drug trade.

Another thing is competitive political games between different partisan factions who use criminal elements to promote instability.