Umm that screams all sorts of red flags your kid needs to be evaluated buy a psychiatrist that is sociopathic or psychopathic behavior, if he had just showed you that would be morbid curiosity but add the eagerness and hysterical laughing and thats socio or psycho behavior.

Get him help immediately. This is very concerning behavior.

First off, get that kid psychologically evaluated. Second, alter the parental settings on all your devices, so he can't do something like this again. And third... GET THAT KID PSYCHOLOGICALLY EVALUATED! Even if he ends up being committed, it's better to be the parent of a kid who was stopped from becoming a murderer than it is to be the parent of a kid who becomes a murderer.

I hope you get that child to a therapist asap. the child obviously needs help.

Yeah, you could waste money on trying to get therapy for this sociopath, but it won't work. What you need to do is show your son a list of people that piss you off, and let him take it from there.

DO NOT allow him to be alone with any animals

Get him some help NOW

Get him some help NOW

1. As others have said, he needs to see a psychiatrist. 2. Younger kids should be monitored when online. They don't necessarily understand yet fiction vs non fiction, sarcasm, etc, and can get super into the wrong parts of the internet. Ex/ 12yro girls (Geyser & Weier) in Wisconsin stabbed their friend multiple times because they read about Slenderman online and thought they had to kill to protect themselves from Slenderman. They have since pleaded mental illness. Monitoring wouldn't change the fact they're ill, but it could have stopped them from finding inspiration.

You weren't paying too much attention to what he reads on the internet and whatnot... Get this kid and you some help.