The characters of Chucho and Father Mundo were written exclusively for Joaquín Cosío and Carlos Cobos respectively.
For the sequence when the Devils (Diablitos) disappear, each extra were filmed separetely and added on Post-Production.
The borough where most of the film takes place does not exist, it is a fictitious town, in real life it's a colony near Tlatelolco in Mexico City.
The chase at the Mexico City's Zocalo was film in one take.
At the end of the Final Credits you will find a recipe for making Romeritos, a traditional food in Mexico cook on Christmas.