I actually saw a video of something like this happening in a store. A woman was harassing another woman who had a very small child in her shopping cart. Suddenly the cops came in, but they grabbed the MAN who had been following both women.

The man, apparently, had been an addict who had come to this store twice before to try to grab small children out of parents' carts, and demanding money from parents to get the kids back. He'd escaped each time. According to NBC, he was finally caught because he had been following the two women from isle to isle, and had ended up in a corner area where there was no real way to get TO the door when the cops showed. So he ended up boxed in and caught.

The women became good friends after that.