Fiance's stalker has resurfaced after 7 years and won't stop sending extremely sexually explicit videos and messages

Posting for my fiance. He had a stalker ten years ago who has recently resurfaced.

We're looking into contacting an attorney to get more info about potentially filing a Civil Harassment Restraining Order (CHRO), but I know restraining orders can be difficult to get, so wanted to get some advice here before we move forward. I'm hoping to hear from others who are familiar with CHROs, specifically regarding the standard of proof & cyberstalking.

The background:

He met this woman once briefly, 10 years ago in college, for about five minutes through a mutual friend. They exchanged no more than a few words and never had a relationship, yet she somehow became fixated on him. For 2-3 years she continually harassed him on social media, sending sexually explicit videos, pictures, and messages, and posted continuously that they were in a serious relationship. At one point she created a fake Twitter account with his name and pictures and tweeted racist and explicit things.

He eventually tracked down her family's info, who confirmed she was struggling with her mental health (I think it was schizophrenia, but I could be wrong) and encouraged him to get the police involved. That cycle finally ended after a police officer called her and asked her to stop contacting him, but nothing formal was filed.

Fast forward to a couple weeks ago and out of the blue the harassment has begun again. I guess she reached out to one of his friends (who she's never met) which seems to have triggered a new wave of abuse.

She's now sending a constant stream of extremely sexually explicit videos and photos (including her and other men), along with obsessive love messages. These are being sent via email (different email addresses everyday) and LinkedIn. She also changed her IG bio to "Ily [his name]" and has been requesting/following his friends on IG and commenting on their photos together.

I understand we need to consult an attorney, but would love any advice! I want to ensure we gather all the evidence we need and that I understand the standard of proof required in CA and/or NY.

Thank you in advance!

Location: We're in California, she's in New York (where they originally met)