Authorities in the northern Mexican state of Tamaulipas plan to scrutinize 9,000 state and municipal police for possible ties to the organized crime groups blamed for hundreds of killings.
The vetting process will be carried out by private firms, state government secretary Morelos Jaime Canseco told reporters.
Another Tamaulipas official said the state government is turning to outside contractors because it wants the investigations to be completed by the end of 2011.
"To meet the goal we have to resort to hiring private services that have national certification," that official said, speaking on condition of anonymity.
Tamaulipas, a Gulf coast state bordering Texas, has made very slow progress compared to other Mexican states in the effort to clean up law enforcement agencies perceived as ridden with corruption, the federal interior ministry says.
Hundreds of officers have been fired nationwide.
Once the bad cops are weeded out, Tamaulipas will begin the task of professionalizing its law enforcement agencies, Canseco said, adding that he is still waiting for the Mexican government to respond to his request for federal agents to be seconded to the state police.
Plagued since the beginning of 2010 by a vicious turf war between the Gulf and Los Zetas drug cartels, Tamaulipas is now the focus of media attention for the nearly 200 bodies recently found in mass graves not far from the U.S. border.
Most of the victims are men kidnapped from passenger buses by Los Zetas gunslingers, possibly with aim of recruiting more foot soldiers for the cartel.