How do I prevent theft and transient moving in while remodeling?

[Ken Lee]

Background:  I have located a quadplex in a low-income neighborhood with NO tenants.  The seller is trying to get rid of the property because he is having trouble remodeling all the units in the quadplex.  He reported that transients moved in and had to kick them out a few times.  The neighbors and others off the street enter the property at night/weekends to steal equipment and building materials. 

This quadplex will take 3 months to finish remodeling.  (Kitchen, bathroom, HVAC (2 units), flooring, windows, paint, etc)

I believe if I can solve these issues, this quadplex might be a good opportunity to fix up and hold as long-term rental units.

Questions:

1.  How can I prevent transients from living in the quadplex?

2.  How can I prevent people from stealing things from the property while renovating?

4.  Should I consider this opportunity?  Even if I can remodel, will there be any red flags holding this quadplex as long-term rental units?