There's tons of seperate issues to unpack, that are brought up by this story.
I've been pretty open on the forum about my infant son"s z"l death five years ago. Since then I've been in contact with dozens of families that had similar stories.
I went through a relatively gentle police interogation, but other families weren't so lucky.
People love to attack the police and say what are they looking for, we don't do stuff like that...
I've always maintained that just wearing a hat and jacket or snood/shaitle does not provide immunity to anger, mental illness, or being overwhelmed to the point of loosing control. This is not the first time tis has happened in our comunities, and unfortunatley likely not the last. B"H usually child services or the extended family become involved, before the police and CK...
One of my children born afterwards was a screamer, and my wife and I got extremely sleep deprived. It was misrable. One night I found myself, seconds from just shaking the baby till she learned how to shut up... B"H I caught myself, and went to get help the next day, - but it can happen to anyone, even a nice calm guy like me.
I've heard from profesionals in the field that the rates of mothers in our community on anti depression meds is much higher than the general population, which has to to with the unreal expectations and demands put on them.
With regard to some people not being capable of being parents -
A. לא תעמוד על דם רעך should apply to the prospective children.
B. Some people are responsible about their childrens capabilities. I know my wife has a married "friend", who can't understand why although she has taken a "fertility" med every day since she got married, as her doctor prescribed her. she has not been able to get pregnant in over a decade. My wife understands exactly why this is being done to this woman, though she feels terrible about her agmas nefesh.