EVERETT, Wash. -- First-degree murder charges were filed Wednesday against a 47-year-old man who prosecutors say now admits to starting a fire as a 12-year-old boy at an Everett college in 1987 that would eventually claim the life of Everett firefighter Gary Parks.

Elmer Nash Jr. pleaded guilty to the charge during an arraignment Thursday in Snohomish County Superior Court, Everett police said.

The fire was set inside the Everett Community College library in Cascade Hall on Feb. 16, 1987 and would swell to a three-alarms. During the firefight, Parks was separated from five fellow firefighters and eventually became trapped inside the burning building and died from smoke inhalation, officials said.

Several potential juvenile suspects had been interviewed in the ensuing investigation that would eventually span decades, but detectives were unable to make substantial progress and the case went cold.

A new detective took over the case in 2016 and his investigation eventually led him to Elmer Nash Jr. as his primary suspect. During multiple interviews in the Snohomish County Jail where Nash was being held on unrelated incidents, Nash discussed details about the fire that only the arsonist would know, Everett police officials said. Nash eventually confessed to starting the fire as a 12-year-old, saying he broke into the library with two other boys looking for items to steal, then set a fire to cover their tracks.

But the fire rapidly got out of control and they ran off.

During the end of the interview, Nash said he wanted to apologize to Parks' daughters, telling the detective: "You tell her that I lit it and it was an accident," according to the charging documents. "I never meant for no one to get hurt.. And I was... I was 12-years-old and I was just being a dummy, being stupid, wasn't thinkin."

The detective said that Nash later recanted his confession saying in later interview he made it up to give closure to the family.

Prosecutors noted that Nash has an extensive criminal history that has resulted in convictions of 14 felonies and 58 misdemeanors as an adult, plus four felony convictions and 10 misdemeanor convictions as a juvenile.

In 2020, the ATF reopened the investigation using newer fire science technology and guidelines to examine the evidence and further prove the fire had been intentionally set, and how.

The investigation culminated with formal charges being filed Wednesday.

"After 34 years, the City of Everett will finally see someone held accountable for the loss of our Firefighter Gary Parks, who died in the service of our community,? Everett Mayor Cassie Franklin said in a news release. ?I commend our city teams for working tirelessly to crack the case and continue towards resolution in this tragic event.?

Everett Community College says the fire leveled Cascade Hall and caused more than $8 million in damages. The blaze consumed an estimated 48,000 books and 19,000 periodicals, including yearbooks and historical records, the college said.

The college replaced Cascade Hall in 1988 with the Gary Parks Student Union Building and John Terrey Library Media Center. A permanent memorial to Parks stands north of the building that carries his name and a bronze firefighter?s helmet and jacket sit on a bench.

?The fire destroyed the heart of the campus and has affected the college for generations,? said Everett Community College President Daria Willis, noting that the college?s logo was inspired by the three spires of the Feather Star sculpture, one of the only parts of Cascade Hall to survive the fire.

The Parks family and his fellow firefighters have since created an EvCC Foundation scholarship to honor Parks? memory. The Gary Parks Memorial Scholarship is awarded to a student enrolled in the college?s Fire Science program.