In English, they do not have to let the Board of Health, The Police, The Fire Department, Maintenance Staff, OR especially a hungry landlord who wants a tuna sandwich from the resident's fridge at 1:26 AM.

Budget cuts led to the police force being reduced and as a result crime spiked.However, I’ve seen very promising signs over the past couple years.

These government agencies have police powers at the state and federal level.

It would be difficult for us to wall it off since the stairwell descends to the back wall where all the fuse boxes and water heater are and then you step left off of a landing...but we could install some sort of security accordion door that could be pushed against one wall like this: https://www.foldingdoorsandroo....  

It sounds like you need a real attorney.If you don't know the identity of the individual, call the police and report a squatter.

Do yourself a favor and obtain council before contacting the police, FBI or any other enforcement agency.

I said selling AT DESCENDING PRICES. 

Or, is your point that a landlord policy isn't appropriate and so two separate polices are necessary, CGL and some other commercial policy for property damage? 

The local police made me aware of what was happening. 

Maybe even his descendants kept that vow???