I’m hoping you’re implying he should be charged with murder. This might be one of those cases where it is much more likely a jury would find him guilty of manslaughter rather than murder.
So, I looked up Mass’s criminal code, and I think I found why they’re doing this. They have a separate section for voluntary manslaughter without a murder charge, and it doesn’t seem to require them to show the defendant intended to murder, only that they intended to cause the injury. Which like I think he very clearly did intend to murder, but a regular person might get tripped up on that.
Murder is strict intent and thus harder to prove. Manslaughter isn’t, you just have to take steps any reasonable person would understand could lead to death or serious bodily injury.