The Mexican government has temporarily removed all of the country's top police from their jobs and will require them to prove that they will not be corrupted in the fight against drug trafficking.
The Public Safety Secretary says 284 high-ranking police will be forced to undergo what he called a "trust test".
The officers will have to take anti-doping exams, polygraph tests and psychological reviews. Friends and the families of the officers will be investigated for possible connections to drug gangs.
And the government will check to make sure that the officers' assets are not out of line with their incomes.