Do serial killers live a double life? 

For this question I will, again, use the interviews with John Douglas and Jack Levin.

Some serial killers live a double life. This makes it easier for them to kill, because no one suspects them. This is something we clearly see with Ted Bundy. Police suspected him twice but he had a very good reputation as a law student and he was politically active, so they forgot about him.  

This is what we see with more serial killers. They live a normal life; they have a wife, kids and a job. They seem to be normal. These serial killers are more difficult to apprehend.

Other serial killers don’t have a double life. They are more dysfunctional and those serial killers are much easier to identify and apprehend.

Source:

Interview: Douglas, J. & Levin, J.