Joseph Naso, ‘Alphabet Killer,’ paid twisted homage to executed ‘Red Light Bandit’: investigator

Joseph Naso, the "Alphabet Killer," may have been paying twisted homage to a death row inmate.

The assertion was made by retired FBI task force investigator Ken Mains, who is attempting to solve cold cases that may be linked to the 91-year-old. Naso’s crimes are explored in the new Oxygen true crime docuseries, "Death Row Confidential: Secrets of a Serial Killer."

Naso is a former photographer convicted in 2013 of killing four women.

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Joseph Naso listens to proceedings during his arraignment in Marin County Superior Court in San Rafael, Calif. on Wednesday, April 13, 2011. Naso had four counts of murder read to him.  (MediaNews Group/Marin Independent Journal via Getty Images)

"… I was able to get into his brain [during my investigation] and understand that he had an idol, a role model, just like we all do," Mains told Fox News Digital. "His happened to be … Caryl Chessman. And Caryl Chessman was executed in San Quentin State Prison in 1960 … He invited Joe Naso, who was a pen pal of Caryl Chessman’s, to his execution."

"I believe he was killing these double initials as a homage to Caryl Chessman," Mains added.

Naso gained his grim nickname after being found guilty of murdering four women whose first and last names began with the same letter. The victims included Roxene Roggasch, 18; Carmen Colon, 22; Pamela Parsons, 38; and Tracy Tafoya, 31. Their deaths occurred between 1977 and 1994.

Oxygen's true crime docuseries, "Death Row Confidential," explores the case of California man Joseph Naso. (Oxygen)

Behind bars, Naso became chatty with William Noguera, a fellow death row inmate and artist. Noguera was assigned to assist elderly prisoners as part of a prison program for inmates with disabilities. When Naso needed to be pushed in his wheelchair, Noguera was in charge. For more than a decade, Noguera built trust with Naso inside San Quentin.

In the documentary, Noguera says Naso confessed to killing 26 people.

Ken Mains is now a cold case investigator. (Oxygen)

Through their conversations, Noguera learned that Naso was well-versed in the biographies of other notorious serial killers and rapists, Vanity Fair reported. According to the outlet, he expressed a "lifelong devotion" to Chessman, the "Red Light Bandit" of the 1940s. Chessman was convicted of robbery, automobile theft and kidnapping with associated bodily harm, according to the FBI.

According to the outlet, police previously found correspondence between Naso and Chessman, along with an invitation to the 38-year-old’s execution. No letters have been published.

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Caryl Chessman at a news conference before his execution in 1960. The "Red Light Bandit" received the death penalty under California's "Little Lindbergh Law." (Getty Images)

Chessman was executed in 1960 under California’s "Little Lindbergh Law." That allowed him to receive the death penalty for kidnapping with bodily harm. 

The Los Angeles Times reported Chessman had not been convicted of murder. He always maintained his innocence.

Vanity Fair reported that by targeting women with first and last names beginning with the same letter, Naso was commemorating his so-called "mentor."

Joseph Naso (left) talks with his legal adviser Pedro Oliveros as the prosecution made their opening statement on Monday, June 17, 2013, in Marin Superior Court in front of Judge Andrew Sweet. (MediaNews Group/Marin Independent Journal via Getty Images)

Noguera compiled a 300-page dossier filled with cryptic clues, locations and partial confessions Naso shared. He reached out to Mains from behind bars and provided the files.

Mains said some of the information would only have been known by investigators closely tied to the case.

Convicted serial killer Joseph Naso appears in front of Judge Andrew Sweet for his death sentence in Marin Superior Court on Friday, Nov. 22, 2013, in San Rafael, Calif. He maintained that the prosecution did not prove its case. (MediaNews Group/Marin Independent Journal via Getty Images)

"He had my attention at that point," said Mains. "I knew that the information he had was credible."

Mains said Naso’s hatred for women began early in life.

"It stems back to his childhood and his hatred for his mother," he explained. "His mother had caught him dressing up in girl’s lingerie. She beat him, and he ended up killing her pet bird, squishing it in his hand. That was just a precursor to what was to come about his feelings towards women, especially women who he deemed to be women who did not belong in this society. He needed to clean them."

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Joseph Naso's in Black Springs, Nevada, a small community north of Reno, Nevada, seen in 2011.  (Karl Mondon/Media News Group/East Bay Times via Getty Images)

Naso led a double life, hiding his dark secrets. He was a father of two, a Little League coach and a photographer by day. But at night, he was described as a sadistic killer who hunted for victims, offering to take their photograph before killing them. Investigators found photos of what appeared to be dead women, along with a "hit list" containing 10 cryptic descriptions of women.

Joseph Naso (left) makes his closing statements as his legal adviser Pedro Oliveros listens on Aug. 16, 2013, in Marin Superior Court in front of Judge Andrew Sweet, in San Rafael, Calif.  (MediaNews Group/Marin Independent Journal via Getty Images)

"What surprised me the most is just how depraved Joe was and how he continued to operate under the guise of a family man, a Little League coach, a photographer who taught at a college," said Mains. "All those things surprised me … and that makes it scarier."

"He’s very bright, but he’s also very narcissistic," Mains added. "That’s why he represented himself at trial, just like his mentor, Caryl Chessman. It didn’t help him. He is smart, but he thinks he’s the smartest guy in the room."

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Working together, Mains and Noguera linked Naso to several cold cases. Piece by piece, they are putting names to the women Naso once reduced to cryptic notes — and delivering long-awaited answers to grieving families.

In the documentary, Mains is seen going through Naso’s belongings with a former neighbor. According to the program, Naso had 10 mannequins hanging in his garage. Noguera said Naso told him he had 10 favorite kills.

"He kept everything," said Mains. "The amount of information he wrote in journals and scrapbooks … When I found a lighter labeled Reno, Nevada, I wondered, did he take this from a hotel room where he murdered somebody? Is that a trophy? It’s hard to know, but it’s there."

Tracy Tafoya's body was found alongside this cemetery in Marysville, California, in 1994. Joseph Naso lived nearby at the time. He was charged, along with three other murders, with the killing of Tafoya. (Karl Mondon/Media News Group/East Bay Times via Getty Images)

" … I gave everything [to investigators] — Bill’s notes, my investigation," Mains continued. "I turned everything over to the FBI … Anybody who requested it in law enforcement, I shared with. The hope is that they’ll do the right thing and solve these cases."

Based on the notes he studied, Mains said Naso relished hunting to satisfy "that urge."

"It’s a game he plays in his own mind," said Mains.

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The view up Medgar Avenue in Black Springs, Nevada, shows the former home of Joseph Naso, the first house on the left, in 2011. Naso is on death row in California. (Karl Mondon/Media News Group/East Bay Times via Getty Images)

For Mains, it’s crucial to solve the cases before Naso takes any secrets to the grave. In the documentary, Mains is seen sitting down with family members, who have spent decades searching for answers about their murdered loved ones.

"It was emotionally difficult," Mains admitted. "You get the brunt of their anger, their love, their hate. … But just because something’s difficult, it doesn’t mean you run from it. So I was happy to sit there and tell them what happened."

Mains hopes the documentary raises awareness about the cold cases and his quest to solve them.

Joseph Naso has since been moved from San Quentin State Prison in Marin County, Calif. (Smith Collection/Gado/Getty Images)

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"It’s not about me solving these cases," said Mains. "That’s what I do. That’s what I’ve done for decades. The bigger story is Bill Noguera and what he was able to do from behind prison walls. He was punished for killing someone when he was 18, and now he wants to give back. He’s in his 60s and wants to help. That’s what he did, and that’s what he continues to do."

"The bigger story is what you can do with your life," Mains said. "… Redemption is possible. And for the families, their loved ones are not forgotten."

"Death Row Confidential: Secrets of a Serial Killer" is available for streaming on Peacock. Fox News Digital's Stepheny Price contributed to this report.