Ideally, he'd be arrested and tried for murder, but I'm not sure they'll have the evidence they need to get a conviction. Now, if they can at least get him on a charge for not listening to the 911 dispatcher, that'd at least be a small consolation. Sadly, I'm not sure this will have a just ending.
They should try for manslaughter instead of murder - being that you can't say his actions were premeditated it would probably be easier to get a jury to convict on a lesser charge.
[notalawyer] It does look a lot like manslaughter, since he pretty clearly ignored police instructions but at least so far there's reasonable doubt as to his intent to kill the kid. [/notalawyer]