Maybe put in one or two exterior cameras.  

Remove all, change the locks, maybe install a camera or two just in case, and done.

Install cameras everywhere, Motion lights, Alarms.

I agreed to let him put on these camera and he also agreed to patch up and uninstall them when move out, but he fail to do that.  

No mailed check or pick ups.Purchase price 300k and owner is giving 20k towards upgrades/repairs etc Plan is to install surveillance cameras, lights, paint doors and shutters, 2 water heaters and new signage and minor fixes etc.

Once I'm done with the forums related to duck hunting, shotgun reloading, MIG welding, heavy equipment work (dozer & skidsteer) and weightlifting; I go to this forum for STRs.I mainly like to share my horror stories...someone overdosing, entering a vacant STR when there is an intruder inside, watching another intruder break in a house live on a security camera, tenants having affairs with other tenants spouses, disconnecting utilities to encourage problem tenants to leave, etc.

Install security system and cameras.

Pretty easy to monitor what other people on your same network are doing... 2) A person in the Wi-Fi can scan all devices connected to that Wi-Fi... this has now become common since there were a few prominent cases of creepy hosts with hidden cameras to spy on their guests (use a 3rd wi-fi if you want to hide other legitimate equipment for this reason to avoid misunderstanding — e.g. a doorbell camera pointed OUT of the property).  3) You can control the bandwidth of each network and keep it balanced 50/50... so if one guest is running 5 Netflix shows doesn’t impact the speed of the other

After getting a camera down, there seems to be a whole and then issues further down the line.Called so many plumbers I've lost count.

@Jacob KlineDo a video walkthrough and show it to potential buyers, explain the situation to them and if it's a good deal they will be okay putting an offer in and buying the place as is.Make sure to check with a local RE lawyer about entering the property with a 24-48 hours notice, on some states it most be mentioned on the lease, I assume there is no lease, so it may be trespassing, also if you are able to legally go in to the property when the tenant is not present make sure to have a video camera rolling all the time so she doesn't claim something went missing.