I’m not a lawyer, and certainly not a criminal lawyer, but I’m not completely convinced that analysis is the best one. The ‘intent to kill’ generally applies when the person doing the act didn’t think it would kill the victim (Example: someone walks into a room and turns on the light switch. Unknown to them, victim was working on the circuit and gets electrocuted. The person didn’t mean to kill anyone. No mens rea)
But for all we know the dosed person was screaming “I’m going to kill you, you f----ing f—!”, right before pumping six bullets into the victim, checking for a pulse, reloading, firing six more bullets, and then yelling “Now I’ve killed you!”. Kind of hard to argue that the person wasn’t trying to kill the victim.
But you can argue the person wasn’t in their right mind.
It’s slightly different. For instance, generally, the burden of proof is on the defense to prove insanity, whereas the defense can just point out that the prosecution didn’t prove intent.