How do you trust people online?

I met Audrey on facebook.
We became friends and chatted almost daily for about 6 months prior to her moving here to Tucson, where I live.

I was just starting to get back to living and had moved into my own apartment. I was in physical therapy finally after three years. I was walking better, but still using a hiking stick to steady myself.
Audrey moved here from South Africa with her family and rented a house with a pool. I have three boys, and she had three boys, and we all seemed to get along great. Her husband grilled steaks for everybody and we all swam together in the pool. After a few months, they talked me into moving out of my apartment, and I moved into the guesthouse, thinking we were buddies ya know? We had made plans for the summer and I was up for friends and fun!

The worst part was, that I really really thought I had made a friend in her. It all went bad when her husband had to go back to South Africa to finish a deal with his work. After he left...I figured out that she was on drugs. Like meth. (her poor kids)
She ended up making fun of me verbally. She’d have the craziest rude people over to swim and say shitting things to me. Having a brain injury makes you really emotional so she literally made me cry…and then fucked with me over it. She started yelling matches with me over the silliest things and basically just went nut. She kicked me out AND then wouldn’t let me get my stuff until I called the cops to help me.

She pretty much freaked me out. She told me she had a gun! LIke shit...does that mean you'll used it???? I literally felt like I was escaping and even her husband ended up calling me from South Africa asking me to help him understand why she was draining their bank account. I felt so bad for the dude so I told him. Your wife's on meth. You need to get back here for your kids.

I ended up having to move to the only place I could find. This lady had a room to rent in a house that she said she was remodeling (that's why it was a mess) NOPE! She was just a freakin' weird hoarder. I lasted about 2 months.

Even work related...I find the people that are scamming!
I had a guy contact me via my website. Small business, wanted certain work, I gave my quote and asked for standard deposit. He agreed, THEN he texted me supposedly from the hospital. AND needless to say it was a whole stupid scam. I've had a few people do similar things via facebook or google or other socials. Its really annoying and after my experience with Audrey back then, I feel like I let my guard down at my own risk.

Freelancing is basically SOME risk. So personally AND doing work independently online how do you avoid finding the dirtbags?
Do you freelance or work online in some way?
Do you check people out? If so how?

I feel really bad to ever judge someone based on what someone else did. But at the same time I gotta look out for myself. How do you grow to trust people online?