The Evidence of the Film is a 1913 American silent short crime film directed by Lawrence Marston and Edwin Thanhouser starring William Garwood.
The Evidence of the Film tells the story of a messenger boy at a film studio who is wrongfully accused of stealing bonds worth 20,000. He is saved by his sister, a film cutter, who comes across some footage of her brother inadvertently walking into a location shot and being knocked down by the reallife villain.
Source: Wikipedia