Honestly having read through the thread this seems a lot less like any individuals being arseholes and more a deep systematic failure of capitalism.

The landlord was very clearly mentally ill and not coping in such a way that anyone who interacted with them for more than a few minutes would not choose to place that landlord in a position of power over themselves.

But in the US Capitalist system being a landlord is a position of immense (and unjust) power that involves very little responsibility and whose only requirement of obtaining is buying a house and renting it out.

During the renting process the tenants to be interacted with the landlord and noticed they were clearly unwell but as the power in the tenant/landlord relationship is so fully in the landlords hands they didn't have the opportunity to do a background check on the landlord (any of whose friends, family, coworkers, or criminal record could have told them they were entering into an unsafe situation) and they ignored what they observed because they had so few choices again, because the power imbalance was so skewed.

I don't think the landlord in question particularly deserves to be punished, let alone subjected to whatever the US carceral system is going to do to a paranoiac, they clearly need help and not to be given the role of a property manager.

What needed to happen was for the role of a property manager to have some requirement other than "has the money (probably from their parents if they're rich enough to cover someone's rent and deposit out of pocket at a moments notice)", for people unable to work because of their disabilities to have a way of living comfortably without being put into unjust positions of power over strangers and for people moving to study or work without ridiculous amount of cash don't have to ignore warning signs and enter into unsafe situations simply because they don't have any better options.

I hope someday I live in a world where that's true in the US.