If it seems too good to be true...
Agreed with madgey- it's very likely in a low income area, meaning your vacancy rates will be much higher than 5% (which is often optimistic even in a nice area), and repairs much more. Also many more expenses (higher repairs when tenants trash the place, turn it into a meth lab, etc.) and credit loss (I.e. them not paying) and legal (evictions).
Search "war zone" on BiggerPockets.Yields of 15-20% aren't uncommon in areas like this, the problem is collecting rent and making it happen. You need to be an "enforcer" type landlord with a strong backbone to deal with those tenants. And if it's a long distance landlording thing, that type of investing is almost impossible, as you won't find property managers who will deal with those types of properties. Or, if they do, they won't bother much, because they know you have no alternative.
Ask yourself why no one else is snatching that up.
All that being said, if you are local, do want to deal with the many headaches that come with those type of properties, you very likely can get 15-20% returns. They do exist. Yet most stay away, for good reason (or start out there, and quickly regret it).
Essentially the reason why they pay such good returns is twofold - a lot higher risk, and lack of competition due to the extra work, stress, and headaches they provide. They HAVE to provide higher returns to compensate for all of that. If people wanted them, prices would rise, and yield would drop. No one wants = low cost = high yield.
Bottom line: if it seems to good to be true, there's a catch. That's the catch with these type of properties. They can produce fantastic cash on cash returns. You have to decide if it's worth it.
I personally like 10-12% in a middle class working neighborhood with no hassles than 16-18% in a war zone.
Best of luck, and let us know how it turns out!