It sounds like something from a Tarantino film (from The BBC) especially the ‘Divine Justice’ bit. I wonder if they had enough time for biblical quotations.

Armed, masked men have burst into a bar in Mexico and flung five human heads onto a crowded dance floor, in an apparent warning to a rival drug gang. An official said 20 men entered the bar in Uruapan city, Michoacan state, fired into the air, forced revellers to lie down and then “threw down five heads”.

The men also left behind a note saying the act was “divine justice” carried out on behalf of “the family”.