>> garza: exactly. >> pitts: ramon garza has been an investigative journalist in mexico for 35 years. he says santiago became a safe haven for wealthy drug cartel bosses who blended in with the town's other wealthy residents. >> garza: it's a place where you can hide your activities, because it's a place for tourism, for... for nice homes, for weekends. >> pitts: and for years, the drug trafficking organization in control of the region, including monterrey and santiago, was the gulf cartel. their enforcers-- the zetas, a ruthless gang that started with former army officers from mexico's elite special forces. hired guns. >> garza: hired... >> pitts: well-trained hired guns. >> garza: well-trained... it... they were like a... like a swat. >> pitts: trained originally to go after the cartels... >> garza: exactly. >> pitts: ...and now they're part of the cartel. >> garza: exactly. they became the army for the cartels. >> pitts: in february, only three months after becoming mayor, cavazos was caught in a feud when the two cartels split. by then, many of santiago's police were on the payrol