Cam, you said you released some of the money. Does that mean you still have some in escrow? If so, I think you should be able to get the remaining balance. I will let a moderator clarify.
I am primarily a freelancer, I browse the client forum because I sometimes need to hire someone for my own projects. As a freelancer: Whenever there is anything remaining in escrow for a closed contract Upwork notifies me that they will refund that to the client unless I dispute. I don't see how this freelancer would win the dispute since he/she didn't submit any work.
For other clients... Most freelancers here are honest, but sadly there are some scammers. There are some who plagiarize other freelancer's profiles, use stock photos for their profile, or who try to appear like they are in a different country. Some also steal portfolio items. If it is a higher end project, it may be worth doing a quick video or phone chat with the freelancer.
Also, you can do a reverse image search via Google Chrome to see where else the profile photo appeared. And you can Google a key paragraph from the profile. After reading or hearing a few client horror stories, I would personally do that before hiring.
Freelancers have to deal with a lot of scam clients too. I wish Upwork would weed out the most obvious since they are often easy for a trained eye to spot and they make this platform a little worse for everyone (both clients and freelancers). I think the ID verification will help, but it will take Upwork a while before they catch up on verifying everyone.
ETA: I know some of this is too late for you, some of it is more for the benefit to any other new clients who may be lurking.
