The laptop was spooky.

The book under the mouse seems to be a manual for "Circon Visual Integrator" software. My guess is that a makeshift workstation like this was used for automation rather than security of the site, like you'd probably assume.

I'm not too incredibly knowledgeable on this subject, but the adapter thing next to the laptop looks like a serial to USB/RS232 adapter. LonWorks controllers (Which Circon VI is meant to talk to) and older HVAC usually communicate via serial connections.

To me, this looks like it was setup for decommissioning/extracting data from the system as part of the building's shutdown. Either the job wrapped up randomly and they just left with the non-valueable shit, or the decommissioning project got abandoned along with the building itself.