Fear pervasive following prison riot that killed 49

A prison riot that left 49 inmates hacked, beaten or burned to death opened searing questions about gang rule, extortion and human rights violations in Mexico's overcrowded prisons, where people merely awaiting trial are mixed in with some of the world's most hardened killers.

Those questions were not abstract for Victoria Casas Gutierrez, a cleaning lady who had waited for hours on Thursday for news of her 21-year-old son, Santiago Garza Casas, who was facing trial for allegedly acting as a lookout for a criminal gang.

Santiago was sent to the Topo Chico prison in September for missing a parole appointment. He was immediately mixed in with a prison population that included murderers.