Other one has been arrested and only been there for a month.

I had squatters once and called the police. 3 officers showed up and told me if I wanted to I could have them arrested immediately.

Apparently the tenant has been arrested for what ever reason and failed to pay rent.

Like happened to my friend whose PM tried to lie out of It once we discovered the tenants felon mug shot and arrest record and 3 evictions the first second he was googled.

I foolishly rented to him and he turned out to be a crooked cop, arrested later for bribery and extortion.

Try to get them arrested for fraud. 

However, if it is a divorce or or other problem, (was arrested, went through rehab, IRS problems, child support problems, or such) the matter hasn't been solved yet and that is a problem.

I just came across this terrible story of an agent who was killed as he was allegedly going to evict a tenant a few months ago. https://www.sltrib.com/news/2019/01/20/three-arrested-death-utah/While there is no total safe space, what do you guys do and recommend so we can do our best to avoid situations like this?

Hard to know if this applies directly, but the US Supreme Court ruled in 1967 that if as a resident you choose not to let inspectors in, they need to get a warrant with probable cause from a judge, they can't simply arrest and/or fine you.

Of the three basic necessities - food, clothing, and shelter - if you shoplift food, you get arrested.