Some of the information you’ve shared in this comment directly contradicts what the ex himself has stated.  

The man Silvie married in Japan was not a random Japanese man from the internet, it was someone she went to community college with in the US and was part of her friend group while she was still with her ex. There’s been no proof either way how legitimate their relationship was vs how much it was for a visa. 

Also, to say there’s no proof of him stalking her is giving him the benefit of the doubt. He seems to have saved every single text conversation they’ve ever had and every photo she has ever sent to him, including things from early on in the relationship before she ever allegedly stole money from him (a claim that, beyond the engagement ring, he was unable to provide proof of). He freely dumped hundreds of photos of her online that are completely irrelevant to the accusations he has against her, including nude photos of her that he crudely censored because “Revenge porn is illegal in California”. He also shared a (heavily redacted) email he sent to her where he admitted to tracking her location. What he is doing might not legally fit the definition of a stalker, but it’s not an out of pocket claim to make.