
Raphael Rowe, who spent 12 years behind bars for a crime he didn't commit, investigates some of the world's toughest prisons from the inside.

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.