Can a person have a sociopathic behavior activate after age 30 when none presented prior to age 30?

First of all, everyone has to agree on the definition, as well as what symptoms are being shown, and when they started. Many do argue that sociopaths start showing signs at a young age, but who was there watching and recording it - or missing it completely, or it was just late starting? Not all sociopaths follow neat little steps of torturing pets or being loners writing about deep dark deeds in notebooks.