In one case, it was physical abuse, which I personally witnessed. A neighbor physically punished his child in my presence, with the child suffering a broken arm due to his use of excessive force in anger.
In the second case, the abuse was sexual and done by a parent. My information there was not through personally observing the abuse, but in recognizing the signs of such abuse in the behavior of a child who was a patron of the library where I volunteered. I discussed my observations with the head librarian, who watched for those signs as well. The child was a 10-year-old girl who spent entire days in the library after being dropped off by a parent. That was "home-schooling" in the minds of the parent. There were several such children in that library, day after day. The library staff tried to help them learn something while they were there, but had other duties, too.
The head librarian took an interest in the child, and befriended her. Eventually, the child revealed the abuse to the librarian, a very kind and patient woman. She reported it to the Child Protective Services office. Their investigator also interviewed me. The child's father was arrested and convicted of incestuous abuse of a child, and went to prison. Both the head librarian and I were witnesses at that trial.
Those are the only two situations where I have reported something. I haven't encountered any other instances.
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