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I am sorry to hear about this situation. Some of what he is doing is legal, and some is not.
The family were essentially tenants for as long as he was working there. Once he was let go, then they ceased being tenants. And unfortunately, he only has to give them a 3 day notice.
However, he cannot turn off water/utilities if they overstay. If they overstay and he has to evict via the court, he has to keep the water/utilities on. This is because they then become tenants at sufferance. This is a weak type of tenancy where they are not supposed to be there, but have remained there after a lease expired pending eviction. The landlord still owes a duty of habitability, meaning that he cannot turn off utilities required for living.
The Court can evict them, however. If he files in Court, then they will have 2-3 weeks before a hearing, and then possibly a few more days before the Sheriff comes out. If they appeal the decision, then they can buy themselves 1-3 months even. However, they will normally have to put down a bond as part of the appeal.
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