Just a week or so ago someone contacted SAR. They will only act with LE involved so LE must take the lead in that situation.
She contacted cadaver dogs and yes, for buildings access need LE to obtain permits etc, but there is no law preventing anybody walking the streets and wastelands with cadaver dogs as long as no trespass occurs.
LE have given no indications they are averse to such a search or any search at all, but we need to be offering them good solid reasons or tips..
This is why I suggested we look at the buildings one-by-one, research each one individually.
Here in Ireland we have a census every year, this census must account for every single person in the country on a certain date and an address of the abode they are occupying on the night of the census.
Is there a similar recording happening in US?
Is it possible to learn names of occupants of every building on certain dates and is this information a public record?
That info would lead us to abandoned unoccupied places that may appear occupied but actually are not and have not been for a very long time.
A building he could conceivably have had access to?
Again, it's tiresome work but LE may be restrained by budgets or all sorts of things, as amateur sleuthers we have no such restrictions.
I wrote to UIC police and I copied their reply here.
It was prompt courteous and interested.
That's enough for me.
They're open to taking a look.
The next bit is the hard laborious process of undertaking such a research intensive project.
Are you up for it?