film related question

Which time? It has happened more than once.

It was in the last twelve months

These are some that resulted in death. There are countless non-lethal accidents also. This week's accidental shooting on a stage in Florida probably brought the question to mind.

1984: Jon-Erik Hexum, an American television actor, died after he shot himself in the head with a prop gun during a break in filming, playing Russian Roulette using a revolver loaded with a single blank cartridge. Hexum apparently was not informed that blanks have gunpowder that explodes into gas with enough force to cause severe injury or death if the weapon is fired as contact shot. This is the principle that gives a powerhead its lethality.

Actor Jon-Erik Hexum died when, during the taping of an episode of the TV series Cover Up, he jokingly put a prop gun to his temple and pulled the trigger. Wadding from the blanks was driven into his skull, and he died of brain damage. Cover Up did not last long, and was canceled in 1985.

1993: Brandon Lee, son of Bruce Lee, was shot and killed by Michael Massee using a prop .44 Magnum gun while filming the movie The Crow. A cartridge with only a primer and a bullet was fired in the pistol prior to the fatal scene; this caused a squib load, in which the primer provided enough force to push the bullet out of the cartridge and into the barrel of the revolver, where it became stuck. The malfunction went unnoticed by the crew, and the same gun was used again later to shoot the death scene. His death was not instantly recognized by the crew or other actors; they believed he was still acting.

interesting but not in the last 12 months

That's all that came up in a search with the detail you provided.