Taser
The taser was actually invented by Jack Cover, who was inspired by the book Tom Swift and His Electric Rifle. He even named the device after the book, “taser” which is basically an acronym for the book’s title. Today this gadget can easily protect us without putting someone’s life on the line.
Actually, one of the X-prize challenges:
https://en.wikipedia.org/wiki/Tricorder_X_Prize
#9 thats not the only thing about that movie that already exists
stun gun