Best approach to neglected duplex owner

[Aaron Jones]

I've found a duplex that is currently either completely vacant or only occupied on one side, possibly by the owner. It's in a great location, and is really a beautiful property but has just been neglected for some time. The owner has done very little to market the property for rent, and it has been at least partially vacant for at least 3 mos.

I'd like to purchase the property to live in one side and rent out the other. What's the best strategy to approach the owner? I need to see the inside to be certain that it could work for my family. Should I mention upfront to the owner that ultimately I'm interested in buying the duplex? Or should I 'pose' as an interested renter for the initial viewing?