Latin America is more susceptible to violent gang activity than the United States or Canada, for a whole host of deep historical reasons.
There are also pockets of the United States at various times that have essentially descended into drug war anarchy, for example some pockets of inner cities. There are deep historical reasons for poverty there that can explain why.
That is an interesting topic to study why certain places have weaker governments, or more corruption, or poverty, or different kinds of economies which make them more susceptible to something like that.
But I think that prohibition creates an illegal market is uncontroversial. Also that illegal markets attract criminal turf wars and gang violence seems pretty uncontroversial to me.