The Star Packer is a 1934 Western film directed by Robert N. Bradbury and starring John Wayne, George "Gabby" Hayes, Yakima Canutt, and Verna Hillie.
Marshal John Travers becomes the sheriff of a turn-of-the-20th century western town where several murders have occurred, hoping to flush out an outlaw known only as "The Shadow".
After watching a stage holdup, Travers and his Indian friend discretely follow the robbers back to the town where the robbers are heard conversing with someone in what seems to be an empty room at the saloon, and later follow them to a hideout close to the Matlock ranch.
After arresting the suspected robbers, Travers makes one of them go back to the special room for instructions, where Travers overhears a plot to murder most of the town with a machine gun coming from the hideout on a wagon, and to murder him from the secret outlook onto the street.
He deputizes the townsfolk and they intercept the machine gun before it gets to town, and he shows them the secret outlook before it can be used to murder again.