Criminality is a very, very high bar for removing people from a community for misbehaviour, and much sexual misconduct isn't criminal. I don't think "leaving things to the police" is good advice in situations where a vulnerable minority group needs to be protected from predatory behaviour.

In this situation you have an accusation of misconduct made by 1) young 2) women 3) new to a community 4) who don't speak English well. These are all big red vulnerability flags.

I would ensure that every accusation of this nature is treated with respect and investigated by a trusted authority figure in a given community.