Mounting cameras, like the GoPro, on firearms may seem like a recent trend but it is not. Back in in at least the 1930s inventors were experimenting with small film cameras attached to pistols. The photo above, dated 1938, is in the National Archive of the Netherlands’ historical photo collection. The camera was connected to the trigger of the .38 Colt revolver. When the trigger was pulled a photo would be taken. The theory was that this would document police shootings.
Many police departments today use camera accessories attached to their Tasers. These devices start recording when the Taser is unholstered.
Many thanks to Ryan for the tip.