The defense attorney is smart in going for what is essentially a PTSD defense.
“There is no reason for killing no matter who” is only true if you are dealing with mentally sound children. It can be broken down like this.
Temporary insanity. Say a boy is intensely claustrophobic, and despite resisting, another boy forces him into a small, dark box. In a state of terror, the claustrophobic boy grabs a pencil and stabs the other boy in the neck, killing him.
In this case, the trauma from being molested by one or two people is such that temporary insanity negates the “cooling off” period that usually distinguishes manslaughter from murder. Mentally, the boy can be described as like being a wild animal trapped in a cage.
That, and the statement by the deceased that he wanted to watch the other boys “squirm”, makes it much easier to argue in behalf of a lesser punishment, likely combined with extended psychological counseling.
I hope you’re right and that it succeeds to at least some extent. The prosecution is trying this 14 y/o child as an adult! I missed that the first time through, but it is shockingly far out of line for the crime. Trial as an adult is reasonable for a career child criminal that age who kills someone in a robbery or commits forcible rape, but not for a disturbed bullying victim.