I'm a 19 year-old college sophomore and work part-time in a grocery store near campus. Yesterday afternoon there was a boy (blonde, overweight, 10-11 years old, wearing a baseball cap and football jersey, holding an iPad) pulling tons of boxes off the shelves and throwing them on the floor. I went over and asked him to stop, and he told me to "go f--k myself." I told him that if we get everything back on the shelves, then I wouldn't tell on him, and we could pretend that this never happened. He screamed, 'I'll rape your mom, ***!' and swiped a whole row of glass bottles off another shelf. Then he went back and stomped all over the boxes he knocked over earlier, and we were up to our ankles in cereal and broken glass. I put my hand on his shoulder, and he kicked me in the shins and ran away. His parents were nowhere in sight, otherwise I would've spoken to them. The incident was caught on the surveillance cameras so the family had to pay for all damages, but his mom is very angry that I put my hand on the boy's shoulder. She kept demanding "Why didn't you try rationalizing to him instead of being violent with a child who's just doing what all children tend to do??"
For future reference, what am I legally and morally allowed to do if a child acts like that in a store? Could someone actually sue me or the grocery store owner for the reasons his mother claimed?
Added (1). I live in Missouri, if this is relevant.
Added (2). I'm not a violent or aggressive person, but I still have a hefty bruise on my left shin. That was the first time in a long time I've wanted to kick someone's @ss
Added (3). What could/should I have done differently?
>>> What is an employee allowed to do if a child is misbehaving in a grocery store?