Rival gangs making peace by submitting their weapons in the casket of a deceased member

Please help me find this movie (scene).
It is supposed to be a lesson about reconciliation between rival gangs,
At the burial of a deceased one, they approach the casket and submit their knifes, pistols
right in the casket, so that animosity between them will be buried for ever.
Don´t know if it is a “christian” movie or not, but sure enough it is a great lesson.Thank you.