One can only speculate at this point, but I wonder if BK started his descent into depravity while studying with Professor Ramsland, who explores the world of the serial killer from the criminal's perspective much as BK's study was designed to do. In 2016, she published her interviews with the BTK killer under the title, "Confession." She was probably working on this book while BK was her student. My view is that BK began to identify with BTK while he was studying under Ramsland. Chillingly, BTK had a personal code for his motto: “D.T.P.G.” stands for “Death to pretty girls.”
It would be easy for a young man with internal and external boundary issues to go to the dark side with this charismatic professor and not find his way back. Much of her work is fiction and fantasy, literally. Some is pseudo-science IMO, including her work on profiling. She seems to acknowledge this point in an
NYT interview:
"Years before she started studying serial killers, Ramsland wrote her Ph.D. dissertation on Soren Kierkegaard, the “father” of existentialism. She sees Kierkegaard as informing her most controversial idea in 'Confession' — that
some serial killers are more like the rest of us than common wisdom tells us. In the annals of serial killers, [BTK] is hardly the only one who held down a facade of normalcy while hunting his prey, but he managed it far longer than many others.
There are many qualities, Ramsland writes, that ordinary people share with so-called monsters: 'overestimating our willpower, idealizing ourselves, daydreaming about power, indulging in secret behaviors that keep attracting us, deceiving others and keeping secrets.' She believes that all of us should lock our doors at night."
She also states in the interview: "Sometimes I think I may be a psychopath." Interesting woman.