He is known as the most prolific serial killer in the history of the United States, but he was as nice and normal as they come. Gary Ridgway, aka the Green River Killer, lived a normal life even though he is believed to have murdered more than 90 women throughout the 1980s and 1990s. Gary pleaded guilty to 48 murders in 2003, and he is currently serving a life sentence without parole. Now, in Oxygen’s upcoming episode of Criminal Confessions, true crime aficionados will be able to find out how FBI profiler, Dr. Mary Ellen O’Toole helped authorities to get inside Gary’s mind in order to get him to confess. In an exclusive interview with In Touch, Dr. O’Toole opened up about what it was like sitting face-to-face Gary.

“The reality of the number of murders that Gary committed really stood out to me. He was a quiet, somewhat demure man, physically unremarkable, basically an average guy, and to know that he was capable of murdering so many women was impressive,” Dr. O’Toole exclusively told In Touch. “I also found it interesting that he was not an angry man. He seemed to enjoy being interviewed by the women, and he came across as respectful toward us. He did not swear (or seldom did so). Likewise, he did not use derogatory terms referring to women, which was in part, why women around him saw him as not capable of being a serial sexual killer.”

O’Toole said that during her time spent talking with Gary, she learned that he was “proud” of himself and of his crimes. “He had status and importance in his mind, because of the number of murders he committed and got away with for decades,” O’Toole continued. “It appeared he was not troubled by his behavior and evidenced no remorse for his actions — and certainly no remorse for his victims or their families. To witness the absolute absence of guilt and empathy for such stunningly, aberrant behavior is something I will never forget.”

Another chilling revelation about Gary’s case was the fact that he was able to lead a normal, productive life outside of his murders: he worked a regular job, went to church, and even married three times. His third wife, Judith Ridgway, even told the local paper Seattle Post-Intelligencer that she had no idea that her husband of 13 years was capable of committing such horrific crimes. O’Toole explained that Gary was able to live a double life because he was different from most other serial killers.

“There may have been behaviors that Judith witnessed [regarding] Gary’s criminal behavior that she normalized, minimized, ignored or just explained away. But Gary’s normalcy in his appearance and in his lifestyle afforded him the protection he needed to fly under the radar screen, in both his private and personal life,” O’Toole told In Touch. “He intentionally kept his murders to himself. The victims were his possessions, and his murderous behavior was relegated to his secret life — to be enjoyed and relished only by him. He did not share what he was doing with others. Gary is not as narcissistic as other serial sexual killers I’ve interviewed, and therefore he was not compelled to brag about his behavior or inject himself back into the investigation. He remained quietly content about what he was doing. His control and secrecy likely kept Judith in the dark about his behavior.”

Criminal Confessions airs on Oxygen on Saturdays at 6 p.m. EST/PST.

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