Investigative journalist Raphael Rowe spends a few days -- both as a guard and a prisoner -- inside Brazil's gang-filled Porto Velho Penitentiary.

Ukraine's Zhytomyr Prison is operated with a skeleton crew that allows prisoners to freely roam the grounds -- often with potentially dangerous weapons.

Raphael Rowe visits the short-staffed Bomana Prison in Papua New Guinea, where near-constant food shortages keep the facility on the brink of chaos.

In Belize Central Prison, the inmates are told that rehabilitation comes through God. Raphael Rowe investigates if this evangelical approach works.