Question regarding Dennis Rader(BTK killer) and salvation.

I am quite baffled when I look at this case, due to the fact that I cannot understand how someone could claim to be a christian, who attended church, heard the gospel and was a respected church official and yet could go on and kill 10 people over a period of time without any remorse if he was saved to begin with. I believe that he still considers himself to be christian and reads his bible.

This question might be stupid but how does once saved always saved fit into this? If Dennis Rader truly believes in Jesus Christ as Lord and Savior, then is he still saved despite commiting such heinous crimes or was he never saved to begin with?