Best ways to keep people out of your vacant house?

[Account Closed]

One of my partnerships just purchased a 4-unit building in a rough area of town. We have a couple of other projects going on at the moment so we aren't in a position to fix it up quite yet. In the meantime we have the windows and doors boarded up and "secured." We hadn't had it boarded up more than 24 hours before someone tried to pry off one of the boards. Try as they might, they were not able to access the inside of the property (a win this time!). We made the repair, but I'm sure they will try and try again . 

So I'm reaching out to the ever-insightful and clever BP community! Outside of the obvious boarding up and checking in on the property, are there any other creative methods you've utilized to keep people out of your vacant buildings that have proved effective?

Thanks!