They demanded that the U.S. agents turn over the informant. Desperate, the Americans warned that the U.S. government would retaliate. In the end, Cardenas simply ordered the agents and their informant out of Matamoros. Cardenas represents a different kind of corruption from the scandals that periodically tarnish the Los Angeles Police Department. Cardenas is not just a bad apple.
Analysts note that Mexico has never had a democratic, professional police force.
Authorities used the police to do political espionage or repress demonstrators or opposition politicians, analysts say. As a reward, the police enjoyed impunity. It wasn't thought that the police had to be professional to carry out their function. It's like buying a McDonald's franchise. You pay for everything.