SANTA ANA (CBSLA) – A 51-year-old man pleaded not guilty Wednesday to arson charges in connection with the devastating 23,000-acre Holy Fire which tore through Orange and Riverside counties this summer.

At his arraignment Wednesday, Forrest Gordon Clark pleaded not guilty to one count each of aggravated arson of five or more inhabited structures, arson of inhabited property, arson of forest, criminal threats and two felony counts of resisting and deterring an executive officer, and a sentencing enhancement for arson burning multiple structures.

He faces a maximum sentence of life in prison if convicted.

On Wednesday, Clark did not have any of the verbal outbursts in court which he has displayed in the past. He remains in jail on $1 million bail.

The Orange County Fire Authority (OCFA) released a statement Wednesday afternoon saying authorities do not believe there are any outstanding suspects and the investigation into the 23,136-acre Holy Fire was now closed.

The fire broke out in the Holy Jim Canyon area on Aug. 6 and then marched east into Riverside County towards Lake Elsinore. It destroyed 18 homes in Orange and Riverside counties and forced thousands of people to flee.

On. Aug. 8, just two days after the fire broke out, Clark was arrested.

Clark, a construction worker, has a cabin in Holy Jim Canyon, and arson investigators allegedly uncovered evidence indicating the fire was ignited in the immediate vicinity of his property, according to the OCFA.

A volunteer fireman, Mike Milligan, who has a cabin near Clark’s, claimed Clark had a long-running feud with a neighbor and other cabin owners. In the days prior to the fire, Clark ran through the area screaming and sent Milligan a message warning that “this place will burn,” he said.

“For years, for years, the Forest Service and the Sheriff have dealt with Forrest and his problems,” Milligan told CBS2 back in August.

O.C. Sheriff’s deputies have had multiple encounters with Clark dating back to 2006.

On the morning the Holy Fire erupted, Clark allegedly threatened to kill a neighbor, prosecutors said.

Later that day, he is accused of setting fire to a neighbor’s residence in Holy Jim Canyon. Of the 14 cabins in Clark’s area, his was the only one that did not burn.

Prior to his arrest, deputies had been at Clark’s cabin questioning him since the fire started. They said he talked incoherently about being chased, about his water pressure and finally about the fire. When officials met with Clark, they said he greeted them holding a machete.

Clark’s initial arraignment was suspended in August after several outbursts from him, which prompted O.C. Superior Court Judge Kimberly Menninger to doubt his mental competency to assist in his defense.

O.C. Superior Court Judge Michael Murray ruled on Nov. 28 that Clark was mentally competent to assist in his defense, restarting criminal proceedings against him.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. City News Service contributed to this report.)