Siblings from both sides, the mother and the father?
Obviously, a second marriage, or parents sharing care of kids, living together.
My training from watching movies and TV, tells me that, it was the step-dad, and both he and the mother never reported it and got away with it. The siblings were kept in the dark or were told lies.
TV and the movies teach at-home-private investigators a lot. ;)
You’re right about the step-dad. An unrelated adult male in a household is, statistically, a risk factor for the children. But it doesn’t sound like it was physical violence. The kid was severely undernourished. Mom had to have been complicit with that. Maybe the poor kid was starving and the step-dad landed a fatal blow.
“”TV and the movies teach at-home-private investigators a lot.””
TRUE and when we get fascinated by one, we remember we’ve seen it before. There’s no shortage of such stories so we just find another one to watch. I never thought of myself as an at-home-private investigator but I don’t mind the label.