Anyone on foot is trespassing. Have them arrested -- as many of them -- and as many times -- as needed.
And stay WELL-armed (and visibly so)...
And that rent-a-cop is not a bad idea.
...nor is having your motorcycle gang buddies buzz through the site frequently...
If you're suggesting a solution to the problem this article is addressing then you're wasting your time. The Detroit police will not respond to any complaint that station owner might call in unless someone was killed.......