Electrocution is a nasty injury, and it causes a lot of damage to the body. The best class I ever had at work was a day long seminar about electrical grounding, when we were owned by Boeing, becasue a weldor(my job) died as a result of a ground wire fault in a 440 volt plug. 3 phase 440 curren uses 3 hot wires and a ground wire. internally inside the main extention cord plug the ground wire disconnected, which if a hot wire dead shorts out for some reason, the ground wire carries the current safely back to the power pole. The machine suffered some sort of failure and a hot wire was shorted out inside the machine, but the broken ground wire could not allow the current to flow, leaving the machine electically hot, sitting on rubbe wheels. The next person that only touched the machine completed the circuit, as current passed from his hand, the entrance to the body, and out his feet to the floor. The electical current in those situation flows through the heart, and he was killed instantly.
My neighbor had a shock off a frayed extention cord, that literally locked him onto the hot wire. Electric shock can make you lock on and loose total muscle control where you can not let go, and you die, and it can happen with 120V cords. My friends uncle died under a house drilling a hole for an air conditioning installation, braced himself against a cast iron drain pipe, when the drill shorted out interally. That was back in the 1950's when tools were metal casings, and did not have ground wires, they were 2 wires, a hot and a common, with no 3rd wire ground in them. All tools now have safe 3 wire systems, and many extention cords come with ground fault intercepters, maybe the best investment you can make.
Electrical shock always has an entrance and exit, if you touch with the hand and it exits forinstance from you elbow, it does not pass through the heart. Severe damage to nerves, and you blood arteries/viens does occur, if you remember Newscaster Adrain Alpert lost 2 limbs in a accident where thescoptic antenna hit a power line in the vehicle she was sitting in.
This young boy may have been far lower voltage, and stun guns probably use 2 shallow probs that are controled. In and out, very close togather. NO doubt this was a level of inhuman torture IMHO, and depending on the nature of the shock, voltage, and how he was grounded, could very well casue nerve damage, maybe other damage if their stupity caused electrical impulses to pass into the heart, organs, or his brain.
I may be wrong, but I think the Mother had given her permission for them to do this, thinking it was going to help him.
That grounding class I had was a real eye opener, and one of the most usefull classes we had. Fooling around with some shocking devise on this child (or anyone) is criminal. I hope they hang um from the flagpole.