TL;DR: Sexual harassment cases are very hard to prove. How should they be investigated?

I just learnt today that up until 2014, there was no law in my country that requires employers to investigate sexual harassment claims. Personally I think that was a good thing because as this counts as a physical assault between two adults, such claims should have been escalated to the police in the first place.

With this amendment however, employers are now have legal obligation to investigate such claims in house. This might be a bad thing considering:

1-It is very hard to prove sexual harassment cases

2-HR is not traditionally trained to conduct criminal investigations

3-Employees are can handle such cases however they please. Squeezed by the need to protect the company's corporate image, legal obligations, and expenditures to run the investigations, I won't be surprised if the whole investigation will be handled by a in house kangaroo court more concerned with making things look good on paper vs looking after the employee's welfare, at least with the corporate culture in my country anyway.

It does't look good, but the alternative of taking it to the courts does not make things easier either. Even with more qualified people working on the case, ie. police & medical people for investigation, judge & jury to preside over the whole thing, the fact that little to no proof can be found and other than statements from both sides there nothing much can be used to investigate the whole thing.

So ladies & gentlemen, how do you see such investigation should be run?