MARTINEZ — His high-profile kidnapping and rape of a Bay Area woman made headlines when Vallejo police publicly brushed it off as a hoax and his victim as a liar.

But now, it appears clear that Matthew Muller, 48, was one of Northern California’s most prolific serial abductors with a modus operandi that often involved scouting potential victims and learning everything he could about them.

He was already likely to spend the rest of his life in prison; another sentence delivered last week will make it a guarantee.

On Thursday, Muller appeared in court in Contra Costa County to receive a sentence of life without parole for a 2015 incident where he kidnapped and held three people for ransom in San Ramon, just days after a shocking crime in Vallejo that made him and his victims famous.

In March 2015, Muller broke into the Mare Island home of girlfriend and boyfriend Denise Huskins and Aaron Quinn, taking Huskins and leaving Quinn tied up. He brought Huskins to a cabin in Northern California, sexually assaulting her several times in the ensuing days, then released her in Southern California. While Huskins was missing, Quinn was being interrogated and treated like a murder suspect by Vallejo police, who publicly accused Huskins of faking the entire ordeal after she turned out alive.

Muller wasn’t publicly revealed to be behind the kidnapping until June 2015, when he was arrested in a similar crime in Dublin. Police and federal authorities linked him to the abduction and attacks on Huskins.

The eventual result of the saga was a book — “Victim F”, published in 2021 — as well as the 2024 Netflix series “American Nightmare” in which the couple’s story was told in detail. but the final revelation was yet to come.

After his arrest, Muller — a Harvard-trained lawyer and former Marine — began confessing to similar crimes dating back to 1993. He drew diagrams, laid out what he knew about his victims, and was charged in Santa Clara County with two 2009 home invasions, as well as the San Ramon incident.

For the Vallejo attack, Muller received 40 years in federal prison. In 2022, he was sentenced concurrently to 31 years in state prison after pleading no contest to two felony rape charges that were prosecuted separately in Solano County. During the state case, he was held in Napa State Hospital and ordered to take antipsychotic medication until he was declared legally competent to participate in his defense.

Earlier this year, he received two life sentences for the Santa Clara County home invasions after he pled guilty in January. One victim told the court that the attack “profoundly impacted my life at that time and to this day.”

Alameda County authorities secured a concurrent 10-year prison sentence for a Dublin home invasion that resulted in his capture.

The Santa Clara County cases were definitively linked to Muller thanks to a chance letter-writing exchange initiated by Nick Borges, police chief in the Monterey County city of Seaside.

Borges told reporters at a news conference earlier this year that after watching the Netflix documentary on the Vallejo case, he messaged the couple — since married — on Instagram. That contact led to their participation in a police seminar training hundreds of officers to conduct effective victim interrogations and avoid the embarrassing mistakes by police in Vallejo.

Borges, with the support of the couple, wrote to Muller in prison; in the ensuing correspondence Muller reportedly confessed to the South Bay cases and other crimes with the apparent intent of helping police improve their practices. That included a reference to a San Ramon kidnapping that had never been reported.

In addition to their book and show deals, Huskins Quinn and Quinn received $2.5 million through a lawsuit against Vallejo.

The case has led to another anomaly: law enforcement publicly condemning the work of their peers. Most of that criticism has been aimed at Mathew Mustard, the longtime Vallejo detective who served as the city’s police union president and retired from law enforcement earlier this year. Within Vallejo’s tight-knit, often controversial law enforcement community, he was celebrated; the department promoted Mustard several times after his work on the Muller case, and he received an “Officer of the Year” award in 2015.

Outside of Vallejo, police and prosecutors haven’t held back in describing failures they say allowed Muller to target others before he was brought to justice.

“It’s a shame it has taken 10 years to correct the mistakes made in the original investigation that permitted Muller to terrorize two additional families,” El Dorado County District Attorney Vern Pierson said in a statement following Muller’s sentence in Contra Costa. “Poor interview and investigation practices permitted these additional families to be victimized. Modern science-based interviewing and the diligence of the Quinns and multiple law enforcement agencies are now working to correct that wrong.”

Staff writer Robert Salonga contributed to this report.