@Charles Kennedy I'm glad to hear those properties in Frenchtown are working out for you and you haven't had any break ins. To be honest I'm quiet surprised there hasn't been any crime. I think you're right it's a little better South of Georgia St but literally one street over is where most of the major crimes (murder, etc) occur. I believe with no evidence to back it up that a lot of the major crimes are between drug dealers and other criminal types. I don't think it's normally a criminal breaking into a college students house. Those properties N of Tennessee are right behind many of the best college bars and walking distance to avoid driving is appealing to many college kids. I think if you drove the streets around your rentals on a Friday night it though, it may change your opinion on the quality of the area.
The reason you are getting high returns is due to the area having high risk and other investors aren't that interested in the area so the prices of the houses are low. Not to say it's not the right investment for you, just something many choose to pass over. I just want anybody on Biggerpockets that reads this to get a good understanding of what they are buying in this area.
Personally I prefer to buy in other areas where I can 1.1-1.5% rule properties with low crime, high quality tenants that don't make a lot of money, and in locations where blue collar families tend to stay for longer periods of time.