A report obtained by CNN indicates 140 police officers have been fired -- 74 because they failed "confidence exams" that included polygraph testing and reviews of financial records.
The report indicated others were let go for more serious breaches, CNN said.
Seven officials were fired because they were convicted of crimes such as kidnapping, murder and extortion. Eighteen were fired because they face criminal charges related to organized crime, murder, robbery and extortion, the report said.
"These are positive steps that they are taking to clean up the police force," Andrew Selee, director of the Mexico Institute at the Woodrow Wilson International Center for Scholars, told CNN.