Alondra Luna Nunez, 14, smiles at a news conference upon her arrival at the Guanajuato International Airport in Silao, Mexico, on Wednesday. The Mexican girl, who was taken from a courthouse by police and sent kicking and screaming to the U.S., returned home after DNA tests showed she is not related to a Houston woman searching for her missing daughter. Mario Armas/AP hide caption

itoggle caption Mario Armas/AP

Reproduction of a letter to the National Commission of Human Rights from criminals, drug dealers, murderers and kidnappers in "El Altiplano," Mexico's highest-security prison. Ronaldo Schemidt/AFP/Getty Images hide caption

itoggle caption Ronaldo Schemidt/AFP/Getty Images

The alleged leader of the Zetas drug cartel, Omar Trevino Morales, is taken under custody to be presented to the press at the Attorney General Office's hangar at the airport in Mexico City, on March 4. Mexican authorities captured Trevino Wednesday, dealing a blow to the feared gang and giving the embattled government a second major arrest in a week. Omar Torres/AFP/Getty Images hide caption

itoggle caption Omar Torres/AFP/Getty Images

The 2,100-person Tijuana municipal police force is one of Mexico's largest. It's also the first in the country to employ body cameras for its officers. Washington Post/Getty Images hide caption

itoggle caption Washington Post/Getty Images