Further to that...

After a sign requesting that people clean up any spills ( Especially from their mouths ) seemed to have been torn down, I went to take some rubbish out - And replace the sign.
I noticed then that it had been set fire to... And on my way back in, spotted someone peering out of a stairwell window at me. They hid as soon as I glanced up.

Called cops back, requested a presence this time.
Wish we had a bloody spyhole in that door - Since not only did a bunch of cops show up, but an ambulance - and a paramedic team looked like they were carrying someone out.

Residents? Roaming junkies/jakies looking for somewhere to drink/shoot up?

Meh.

Time to break out the remote sentry cannons...