I would contact an attorney in your area that deals with real estate/landlord tenant law.You should be able to recover for damages as long as you have some evidence of damages, the back rent should be not an issue because you had a court order, if not you have the lease agreement.

Do not provide him evidence that you were snooping and taking pictures in his apartment.  

For the next week I'll simply continue to email them looking at least for a response, that way I at least have the evidence that I've been trying to work with them.

Just get every piece of evidence you can and fight!

In our own properties, we have gathered empirical evidence that providing tenants visibility into their resource consumption almost always leads to reduced resource waste {we still get the odd tenant who simply does not care and would rather set the thermostat at 28C than don a sweater}.  

They like evidence and documentation.

Just can't shake the stigmas.I would definitely go over there to get photographic evidence if you don't have it.

The tenant has the burden of proof to their claim by submitting evidence such as maintenance record requests, photographs, and/or testimony.

A SFH I own was being re-prepped to re-rent and was being advertised by the PM company.Who, as is ever increasingly more evident, apparently do whatever they want, often ignoring what I tell them to do, and then if it's ever questioned they have a version of The Story which makes it all my fault.

Should he encourage the existing tenant to call the police/gather more/better evidence?