Answer:
Most people think of serial killers when you ask this. But although many serial killers are sociopaths, there are far more sociopaths leading ordinary lives. Maybe you have heard the expression, "Psychopaths wear the mask of sanity," but there are millions of sociopaths, most of whom never become serial killers. Statistics are that maybe 1 in 3 persons could be a sociopath and there is no real means to answer your question. If you are dealing with sociopaths, in the related links box below is a good article for your knowledge.