Well something this trivial should not be left up to the cops. I mean if your first reaction to a situation like this is to call the cops then you a tattle teller and nobody likes that. I bet that would drive this guys girls right in the direction of this so called "offender"
How is getting sexually harassed trivial? Ok, maybe if the guy was smacking her butt or pinching it. But, what the guy has done has gone above that now. Trying to lift up her shirt( probably with the intention of touching her breasts as well) and touch her "no no square" has gone criminal, hell it could be called sexual assault now. The next step for this guy is probably rape. He kept on escalating it and wouldn't be surprised if he tried it.