For years Mexico's Tijuana was a battlefield where drug lords ruled the streets – that is until police chief Julian Leyzaola took charge of the force in 2007.
After a sustained attack on the cartels, seizing tonnes of narcotics and rooting the police force of corrupt officers, he turned his attention to Ciudad Juarez – regarded as Mexico's most violent city.
But his endeavours have not been without controversy and the police chief faces accusations of abuse, torture and human rights violations - even from a fellow police officer.
Now many question whether the superintendent can defeat the cartels in Juarez - and if human rights abuses will be the price of that victory.
Al Jazeera's Rob Reynolds reports from Ciudad Juarez, Mexico.