Most of these type of trials are one persons word against another without any real evidence. You would imagine that a similar pattern of behaviour towards multiple women would be enough to convince a jury.
The attempted rape is so much worse than everything else in his pattern though, but of it wasn't reported at the time, it's always going to be tough to prove.
The one I don't understand though, and I hope I don't come across as crass with this, is the allegation of sexual assault in a nightclub by "touching her arms and hips with his hands over her clothing". I mean don't get me wrong, that is creepy old man type behaviour, but I don't understand how it is a sexual assault.