you can't have direct evidence of someones alertness or state of mind, only circumstantial.

the direct evidence from witness testimony is only needed if the shooting is disputed.

assuming the shooting is proven, with no evidence of intent, you can't have murder 1, and likely can't have murder 2 either and are probably stuck with involuntary manslaughter.

obviously it depends on the state.

however even manslaughter requires some requisite knowledge and intention of what you are doing - but proving something like insanity or incapacity is usually on the defense to prove.