SACRAMENTO, Calif. — The man who drugged a Vallejo couple and raped a woman repeatedly in South Lake Tahoe — all recounted in a popular Netflix docuseries released last year — is under investigation for newly unearthed crimes that allegedly stretch back to 1993, when he was a teenager, authorities announced Tuesday.

Matthew Muller, a Harvard lawyer and former Marine who grew up in Sacramento County, is serving a 40-year prison sentence for kidnapping and raping Denise Huskins, now Denise Huskins Quinn, in March 2015 — events that the Vallejo Police Department initially deemed a hoax.

Investigators for 18 hours interrogated Huskins Quinn’s now-husband, Aaron Quinn, accusing him of killing her. Days later, Huskins Quinn reappeared after being dropped off in Southern California. Authorities eventually found evidence linking Muller to the attacks. He was arrested at a South Lake Tahoe cabin where he held Huskins Quinn captive and sexually assaulted her.

The kidnapping, rape and Vallejo Police Department’s mischaracterization of the crimes as a ruse were the subject of the three-part documentary limited series titled “American Nightmare,” released by Netflix in January 2024.

Authorities long suspected Muller in other similar incidents, but did not have enough evidence to arrest him until recently. Prosecutors in recent weeks filed charges against him for incidents in Santa Clara and Contra Costa counties in 2009 and 2015, respectively.

Additionally, the El Dorado County District Attorney’s Office said that in 1993 when Muller was 16, he kidnapped and sexually assaulted a victim.

“He had all the markers of a serial predator,” Huskins Quinn said during a news conference in Seaside. “And it’s unfortunate that it’s taken this long to be able to … give some better clarity and hopefully some sense of peace for these other victims.”

El Dorado County District Attorney Vern Pierson declined Tuesday to give any details about the 1993 case, including whether Muller allegedly committed the crimes in California, because the incident is under investigation. Muller once lived in Orangevale and attended Bella Vista High School in Fair Oaks, according to The Sacramento Bee’s previous reporting.

The revelation of the 1993 incident came to light after Huskins Quinn met with the Seaside Police Department in Monterey County last March for training to help investigators learn how to question victims.

After that meeting, Seaside Police Chief Nick Borges sent Muller a letter in which the now-47-year-old wrote back and confessed to the 1993 kidnapping and sexual assault, Borges said during a news conference.

Pierson and his office, assisted by the FBI, separately reinvestigated Muller in May 2024, “which included a thorough interview during which he admitted even more crimes,” the El Dorado County District Attorney’s Office wrote in a news release.

“We now know Muller began committing kidnapping and sexual assaults at age 16, home invasions in (2009), numerous prowling and peeping, secret recordings and three separate home invasions in 2015,” Pierson said in a statement.

After pleading guilty to kidnapping and ultimately being convicted of rape and several other charges, Muller was sentenced in 2017 to 40 years in federal prison, then in 2022 to 31 years in California state prison, to be served concurrently.

‘Just the tip of the iceberg’

The Bee’s previous reporting in 2015 noted detectives in Santa Clara County suspected Muller as the perpetrator of a home invasion and kidnapping, but did not have enough evidence to arrest him.

Muller was accused of breaking into a Mountain View home in September 2009 and tying up a woman. Muller forced her to drink a “concoction of medications” and said he was going to rape her, according to the Santa Clara County District Attorney’s Office. The victim “persuaded him against it” and Muller suggested she get a dog before fleeing, prosecutors said in a news release.

In the second 2009 incident, Muller bound and gagged a woman at a Palo Alto home and forced her to drink Nyquil, the news release said. He’s accused of assaulting her before “being persuaded to stop” and then fleeing.

Santa Clara County prosecutors said the charges followed “advances in forensic DNA testing,” and that Muller’s DNA was found on straps used to bind one of the victims.

The incidents in Contra Costa County happened about two weeks after the incident involving the Vallejo couple, according to the El Dorado County District Attorney’s Office.

Muller is accused of kidnapping two men and a woman in 2015 in San Ramon and demanding one victim withdraw tens of thousands of dollars. After Muller received the money, he fled, the Contra Costa County District Attorney’s Office said in a news release.

“Fearing retribution, the victims never reported the crime,” prosecutors said in a news release. “To this day, they have chosen to remain anonymous.”

Huskins Quinn became emotional at times as she recalled the terror and what other victims went through. She hopes the developments against Muller can show positive shifts in policing and how to correctly handle investigations.

“I really believe this is just the tip of the iceberg,” Huskins Quinn said, “and that there’s probably more to be learned.”

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