I’m 65. About Wives who have no idea ….my violent husband was probably a sociopath,(lots of affairs, violent, dangerous, planned on killing me and attempted it, stole a ton of money). according to my trauma docs. He also lied to me extensively. Now if you yourself don’t make a habit of lying, you tend to believe people automatically. So I , the wife, was often was very bewildered and confused by lies, thought things were quite weird and strange, but never really thought he was lying to me. I didn’t put all the lies together till years later. Then it all came together and explained the things that seemed odd at the time when I believed his explanations. So wives first thoughts when they encounter clues of serial killers…. (again mine was not a serial killer…just a sociopath the docs think ,but can’t diagnose ) wives don’t instantly leap to “ gee, he‘s probably a serial killer.” Normal people believe each other , especially people they love and married, and look for normal explanations even. amidst abnormal situations. So when people wonder why serial killers wives never knew, I think the brain is always looking for a normal explanation for unexplainable clues. The shock comes later when the truth is revealed. IMHO.