Crime + investigation

Why a UCLA Student’s Roommates Killed Him in the 'Manson Tunnel'

Nathan Blalock and Duncan Martinez almost got away with murdering Ron Baker in the underpass located in Los Angeles’s Chatsworth Park, not far from Charles Manson’s Spahn Ranch.

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Published: August 27, 2025Last Updated: August 27, 2025

In the early hours of June 22, 1990, a group of teenagers discovered a man’s body in the “Manson Tunnel.” The train tunnel, located in Chatsworth Park in Los Angeles, got its nickname because of its proximity to Spahn Ranch, where theManson family had set up camp before the group’s murderous attacks in 1969. People used the tunnel, covered in occult symbols, for strange activities and even animal sacrifices, and police wondered if this death was connected. 

A few days later, the victim was identified as Ron Baker, a 21-year-old studying astrophysics at UCLA. Baker's interest in Wicca heightened questions about a possible occult connection, particularly because he’d been killed on the night of June 21, the summer solstice. 

However, Baker’s parents had received a call demanding a $100,000 ransom for their kidnapped son on the night of his murder. A second demand came the next day. The anonymous caller gave no ransom instructions, but a demand for money didn’t point to the supernatural.  

Baker’s killers turned out to be his two roommates, one of whom gave a eulogy at Baker’s funeral, begetting myriad questions about how and why this shy student was targeted. 

One Killer Got an Immunity Deal  

Baker’s roommates, Duncan Martinez, then 20, and Nathan Blalock, then 22, told police that on the night of June 21, they left Baker at a bus stop. The two also said they’d looked for their roommate in Chatsworth Park, where police learned Baker liked to meditate, after learning about the ransom calls. Police couldn't understand why they thought kidnappers would take Baker to the park since the location where Baker’s body was found had not been disclosed and they started to ask more questions. 

Retired LAPD detective Rick Jackson investigated Baker's murder alongside partner Frank Garcia and wrote about the case in Black Tunnel White Magic: A Murder, a Detective’s Obsession, and ‘90s Los Angeles at the Brink. He tells A&E Crime + Investigation, “We tried to eliminate them [as suspects], because it didn't make sense that they were the ones. Why are you going to pick your roommate, and for Duncan, one of your best friends?” 

Detectives had Martinez take a polygraph test, which he failed. Soon afterward, Martinez called a friend and said he’d been abducted and taken to a Los Angeles-area warehouse. However, police traced the call to an airport in Las Vegas. 

In February 1992, Martinez was arrested in Utah to face charges of passport fraud. He reached out to the LAPD and ended up with limited immunity. “It was only immunity for that day or any following cooperation or people he told us that he had talked to,” Jackson explains. 

A Classic TV Show Inspired the Kidnapping 

Martinez told police that an episode of Dragnet made him and Blalock think about kidnapping someone. Jackson, who spent time with both roommates, says, “I can kind of see these two, who both think they’re a lot smarter than they really were, saying, ‘Hey, yeah, dude, if we decided to do a kidnapping, we wouldn't be stupid like that.’ And, ‘Yeah, we should kidnap somebody and make some quick money.’” 

Martinez and Blalock also discussed that a kidnapping survivor could testify against them. Their plan became a plot to kill, with Baker as the target. 

Despite being roommates, Jackson notes Blalock had never gotten along with Baker. But given their close friendship, Jackson says, “It makes it unbelievable that Duncan at some point didn't step in and say, ‘Hey, wait a minute. What the hell are we talking about here?’”  

The Attack Didn’t Go as Planned 

According to Martinez, the pair lied to Baker that they would meet girls in Chatsworth Park on the night of the solstice. Martinez said he didn’t think the killing would really take place, but also that the murder didn’t happen at the appointed spot and time. Jackson points out, “If you know exactly when and where they were going to be standing, you had to discuss the plot fairly significantly.” 

Martinez claimed the trio was inside the Manson Tunnel when Blalock attacked Baker with a Marine Corps Ka-Bar knife, borrowed from Martinez. Martinez said Baker pleaded for help. Baker was stabbed 18 times and had his throat slit. 

After the murder, Martinez made the ransom calls. Jackson explains that Baker’s parents told their son’s trusted friend that they’d alerted the police, so he knew to stop calling.  

Building a Case 

Jackson says Baker’s death probably occurred at 10 p.m. His body was discovered at 1:30 the next morning when the Manson Tunnel’s macabre associations drew teens there the night of the solstice. A discovery occurring soon after the murder preserved more evidence. 

Following Martinez’s confession, police had blood from under Baker's fingernails tested for foreign blood. The rare type AB showed up. Martinez didn't have that blood type, but Blalock did. Testing used up the sample, so the lab wasn’t able to do DNA analysis, Jackson says. Detectives also had Martinez talk to Blalock, who was locked up on robbery charges. During calls and an in-person meeting, all of which were recorded, Blalock never contradicted Martinez about killing Baker. And on one recording, as Martinez spoke about Baker’s death, Blalock said, “It happened. It was a mistake.” 

Duncan Martinez Walks Free 

Blalock admitted to police that he'd stabbed Baker and was charged with first-degree murder in 1993. Martinez’s immunity deal made it hard to build a case against him, but in December 1993, he tried to break into a store in Utah. After his arrest, Martinez filled a detective in about Baker’s murder, including that he’d urged Blalock to end Baker's suffering by killing him. 

Martinez’s immunity agreement didn’t cover this conversation, which the detective recorded. Jackson says that, due to Martinez's earlier cooperation, prosecutors offered to let him plead guilty to second-degree murder. Wanting an even lighter sentence, Martinez refused. In 1994, he was charged with first-degree murder. 

In two separate trials in 1996, Blalock and Martinez were found guilty of murder under special circumstances. They were each sentenced to life without parole. But in June 2020, Martinez received a sentence commutation after he’d served more than 25 years. The next year, Martinez was paroled. 

Jackson admits he doesn’t know if the case would have been solved without Martinez’s cooperation, but he disagrees with the decision to grant Martinez parole. “I’ve always said that Duncan's role in this—even though most likely he did not do any stabbing—he more than anybody could have stopped this,” Jackson states. “I'm not saying people shouldn't have commutations, but you have to weigh who should get it with who shouldn't.” 

About the author

Sara Kettler

From historical figures to present-day celebrities, Sara Kettler loves to write about people who've led fascinating lives.

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Citation Information

Article title
Why a UCLA Student’s Roommates Killed Him in the 'Manson Tunnel'
Website Name
A&E
Date Accessed
September 25, 2025
Publisher
A&E Television Networks
Last Updated
August 27, 2025
Original Published Date
August 27, 2025
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