This sort of thing happens. You can forget that you have your child with you when you go to the store. You can assume your spouse grabbed the kid out of the car when you got home.
These cases are rarely intentional and the amount of anguish that the perpetrator feels must be extreme. Locking them up will solve nothing. Parenting classes will solve nothing. Accidents happen, people are fallible.
There is no excuse for forgetting you are a parent.
This kind of absurd “accident” should get you jail time. An adult’s negligence (or intent) caused the tortuous death of another human being.
This actually happened to us when my son was a baby. I hurried from the car to the house, laden with a diaper bag, etc., to run to the bathroom. When I came back to the living room I asked my husband if he brought the baby in. He said no, I thought you did. But this was minutes, not hours. It is very noticeable if your baby is not in the house, especially a crawling, curious 10 month old. My youngest grandson is 10 mos old now. I can't imagine overlooking that he's not in the house.
With each passing year it happens more frequently. If there were appropriate punishment, I bet the parents would be less forgetful. And I’m sorry for the parents’ pain, but shouldn’t we focus more on the child?