On the lease we'll have the tenants initial after every addendum.If for some reason our LLC operating company is negligent, it should be set up to isolate itself from all other assets held by separate LLC's.

Is it possible I need to find someone to seal the foundation of our building to ensure they can't get in from outside, and then once the indoor population is isolated try to stamp them out? 

You need to shut off the water at each unit or to each device in each unit (every sink, toilet, etc) and then turn them all back on one by one to isolate your issue. 

It wasn't prosecuted and it is an isolated incident in their criminal history (other than that, it's totally clean). 

Besides technology wise, I think future communities will be closer nit and communal instead of everyone having their own Isolated McMansion.

Since neither Chris or Bo "chimed- in" on this (despite my email, on their website...) it does look like they do "isolate, team members" even with the "basic" membership plan, as I just saw on the following YT video, at about 15:15 mins. into it. : "How to Lease Option Real Estate without Money or Credit Part 3 of 3" on the "Chris Goff' YouTube channel.

The officer I spoke with said it was an isolated incident of drunken people acting like idiots.  

And mine was not an isolated instance, they were doing this sort of thing right, left, and center in 2008-2009. 

How can I isolate the best areas to invest in multifamilies in Allegheny County?

I would be surprised if the state can force your parents into 'not replacing' an existing bridge which would isolate them from public access.