They had stolen the batteries out of them. 

There was stuff and trash everywhere, at some point it had squatters living in it, there was graffiti on the exterior, and all the copper pipes and wiring had been stolen out of the house.

Between initial contract and acquisition the HVAC unit was stolen, and some additional damage done.

This neighborhood is notorious for being broken into and having the copper cut out and stolen. 

If that doesn't work, or it's not easy to do, then work on your backup process.Also consider what happens if the computer that you do all your work on is damaged or stolen. 

Buying houses (I mean, merchandise) for flips fit that description hence classification of being a real estate dealer and subject to the self employment tax.

There's a lot of incredibly fascinating stories about the dark-net drug markets that were the initial heavy users of bitcoins either getting stolen from, hacked, or pulling "exit scams" where they just shut down and ran off with the "escrow" accounts.  

I've never had a huge issue with theft or stolen items so that doesn't really keep me up at night but if somebody stole an air conditioner I keep extras at my warehouse and that would be a cheap rrplacement but I wouldn't put the replacement condenser until the Spring.

The guys is not ex-military (stolen Valor) but ex-con who did time for selling drugs, he doesn't know anything about construction or rehab and will endanger your project with thousands worth of damages.

Oh, and another method that may help is that you require tenants to have renters insurance, its only like $4.00 a month here, this will help in instances where things may be stolen..