What? They don't get paid according to the amount of crime, they get a salary from whichever government budget is set for their municipality. Mexican police tend to be understaffed and underworked, so it's no surprise things get by them all the time. The government reaction also appears to stem more from the premise of the state asserting it's monopoly on violence rather than whether or not they actually want to solve any problems. I think their silence on what caused the vigilantes to do what they do speaks volumes to how much they care about the actual crime and broken system that facilitates it, though.