In my area, copper theft is typically seen in vacant houses where drug addicts break in to steal mostly the copper pipes but sometimes some wire as well. 

:Class A Properties:Cashflow vs Appreciation: Typically, 3-5 years for positive cashflow, but you get highest relative rent & value appreciation.Vacancy Est: Historically 10%, 5% the more recent norm.Tenant Pool: Majority will have FICO scores of 680+, zero evictions in last 7 years.Class B Properties:Cashflow vs Appreciation: Typically, decent amount of relative rent & value appreciation.Vacancy Est: Historically 10%, 5% should be applied only if proper research done to support.Tenant Pool: Majority will have FICO scores of 620-680, some blemishes, but should have no evictions in last 5 yearsClass C Properties:Cashflow vs Appreciation: Typically, high cashflow and at the lower end of relative rent & value appreciation.

For newly constructed, purchased or renovated properties and also retroactive generally over the last 10 years, building components are properly classified into individual units of property and accurate recovery periods for computing depreciation deductions.

My boyfriend is an electrical contractor with experience in all areas of construction and our plan was to build the duplexes ourselves and I would then manage the rentals for my investors.

If flipping is your end goal I would get an education in construction.

I typically look at Multi-Unit rehab, and hold.

There is a lot of new construction there.

I'm also thinking it might be better to buy near hospitals/universities/tech companies/factories.Am I missing anything, or is this typically the research one should do before buying an investment property?

Quote from @Madhul Shah: If an individual purchases a rental property and incurs expenses for property management, maintenance, and mortgage interest, how are these expenses typically treated for tax purposes, and what impact do they have on the individual's taxable income from the rental property? 

What percentage of the sales price one would expect a seller to typically accept?