7Gun-Mounted Camera (1934)
It probably says something about humanity that we invented the camera gun over half a century before the camera phone. Things only get grimmer when you read the operating instructions:
Photographic identification of fleeing criminals may be obtained with a recently perfected camera which is attached to a pistol or rifle and worked by the gun's trigger.
Worked by the gun's trigger? We wouldn't trust RoboCop to differentiate between a criminal fleeing and what we would do if you pointed a gun at our face and repeatedly pulled the trigger while telling us to smile. Add the clearly bloodthirsty cops of the 1930s to the equation, and we're not feeling great about their willingness to learn to pull the trigger lightly to take a photo, and not pull it all the way. We have a feeling that this gun ended up taking more pictures of Rorschach blobs of brain matter frozen in place on whatever the terrified "criminal" happened to be standing in front of.
POW! "Haha, you should've seen the look on your face! Wait till the boys at the station see this one!"
6Vehicles and Pedestrians and Bullets, Oh My! (1922, 1959)
When the Thompson submachine gun -- a gun capable of firing a thousand .45-caliber bullets per minute -- was introduced in the early 1920s, the law enforcement community's first thought was "Let's strap that fucker to a motorcycle." Spraying a steady stream of hot lead while weaving between lanes might seem impractical, and it is; we should point out that the gun came loaded with military grade ammunition as well as birdshot. Sure, birdshot could still pepper innocent, sidewalk-bound bystanders with thousands of tiny, survivable wounds. But still. Motorcycle machine guns, you guys!
We at least hope they included an easy dismounting system so the gun could be popped off when the officers parked the bike to grab some lunch, rather than leaving a loaded machine gun out on the street. But we have to assume they didn't, since these were the same people who designed a motorcycle-mounted machine gun at a time when they were still figuring out which color lights should mean stop and go.
It was the '20s, so the average toddler probably had more firearms experience than modern Marines.
The modern lack of non-tank vehicle-mounted firepower in civilian areas tells us that they at least learned their lesson. Except that, nearly 40 years later, the same magazine highlighted a car-hood-mounted gun designed for Texas Rangers and fired by some kind of pistol grip arcade controller sticking out of the car's dashboard.
Texas summers are hot. Why leave your air-conditioned squad car just to shoot a dude?
We're assuming this had less to do with inexperience and more to do with the world generally being tired of waiting around for video games to be invented.