Even at the tender year of 10, I of COURSE knew what death was. And of COURSE as a human being knew that KILLING someone was wrong.
Having said that, this kid shouldn't be tried as an adult, but he should be watched, very closely.
See if he delights in torturing animals, sets fires, wets his bed, etc.
BTW, whenever an adult dies under suspicious circumstances, who is suspect #1? The spouse. Until proven otherwise.
And to add to that, who benefited?
If the spouse benefits, put EXTRA investigation on them.
I have never heard about bedwetting as an indicator of anything except certain allergies. One of the gentlest men I ever knew had been a bedwetter as a child; but as an adult was extremely genial and only took out his physical strength on tennis balls. Can you link or explain the tie-in to violence?