The claims of around half a dozen WG's giving explicit warnings about his instability & threats are suddenly hearsay! Why would any girl make a claim, let alone half a dozen girls if it wasn't true.
If he has talked to you about giving a good reference to the police, then that itself should ring alarm bells as to WHY the police are involved. He must have done something to get them involved and now he wants to use the girls he's seen before to protect his reputation and refute allegations against him. Luckily most girls are wise enough not to fall for his trick, and those that refuse may fall prey to his evil threats of revenge.
His meltdowns and character is documented on this website. If you have a spare few hours, just read through his posts through his various usernames, most notably marty mcfly, columbo and asian beast. He's also contacted many punters asking very personal questions and acting weird. Again, most punters are vigilant about revealing any personal information about themselves, so too should any WG. He's a nast piece of work and yes he may be nice when you see him but history also tells us that many criminals gain the trust of their victims before they strike.
Stop banging on about screenshots, it makes you look suspicious. If you really are worried about your safety then screenshots won't keep you secure, it's common sense that will.