I thought you meant the cartels were killing a lot of innocents civilians(even family members of police or any government job) which doesn't/rarely happens yes of course a lot of police of all levels, military, and politicians corrupt or not have been killed obviously but a lot of the dead are still criminals killing criminals. Now about the heat thing:some cartels cells just dedicate themselves to bring heat towards a rival plaza so that they confront their rival gunmen if the local/state/federal police(in some places) and politicians corrupt or not can't stop them, if it gets too out of control the state governor or Calderon will have to deploy army troops and federal forces to that area/town/city thus affecting the relationship of the rivals's with the local or state police/ politicians.
Obviously rival cartel members make up most of the 34,000 + killed since this all began back in 2006. Meaning innocents do make up the minority. But over the last 5 years, those numbers have added up.
I should also point out that the cartels have been known to go into their rival's territory and kill innocent people as a way to bring down heat on their enemies.
