It could be a number of reasons as to why the houses are being turned over within a few years of purchase.
Perhaps the owners bought the property as an investment and changed their minds, or maybe the owners are needing to relocate.
If you would like to find out about any issues with the property, talk to the neighbors. I showed a property to a client yesterday and within 5 minutes into the showing one of the neighbors was sticking her head in the door to find out who we were and what we were doing. Then she started spilling her guts about not only the property but the owner, neighbors, community issues, everything we could want to know and more. Believe me, some neighbors are a veritable gold mine of information!