When thinking about the latter, a 5-year-old is a very useful witness for someone she recognizes, but not very much so with a stranger (abstract thinking and related takes time to develop).Someone with rage and/or someone who felt they couldn’t afford to leave a witness.
When thinking about rage, once again, first thought is something personal.
But - the partners are ruled out and there is still no suspect.
So what are we left with? Either someone the 5-year-old knows that is not one of the partners that has been ruled out.
Or someone irrationally angry due to drugs.
I don't want to sound sexist, but either way it feels to me that most likely a POI would be a man, and a younger man. I think the aspect of shooting a toddler makes me feel this way, somehow. Not because "a women would never do it", but to risk attacking someone when there is 2 adults and a toddler? Using a gun. And quite successfully, unfortunately. Shooting a (probably) "just happened to be there" bystander (whichever of the women in was, unsure). Shooting a 5-year-old. All of them together kinda point to a fit and angry younger male in my head, any of them alone is meh, but combined... Just thinking out loud for now, as we lack info.