Guard Says He Set Film Studio Fire : Court: Guilty plea in blaze at Universal comes shortly before his trial was to start. He is sentenced to four years in prison.

On the eve of his trial, a former Universal Studios security guard did an about-face and pleaded guilty to arson Thursday in connection with a dramatic blaze that roared through the studio back lot on Election Night 1990, destroying four acres of sets and causing $25 million in damage.

Michael J. Huston, 41, of Tujunga, admitted his guilt before Superior Court Judge William R. Pounders, who immediately sentenced Huston to four years in state prison.

“I guess I’d have to tell you it was primarily because he was absolutely sick of the L.A. County Jail,” Huston’s lawyer, Charles English, said in explaining the turnabout. English said Huston, who has been in jail since his arrest the morning after the fire, expected to be sent to state prison for the crime and believed Pounders would be fair in sentencing him.

During the 15-minute hearing, English told the judge that his client--who had earlier confessed to the crime but blamed it on having a split personality--never intended the fire to cause so much damage.

“The one thing that Michael most wanted said on his behalf was that he didn’t intend to do any kind of a fire like this,” English said afterward. “He started a fire in a trash barrel with some newspapers and a Bic lighter. He did not intend to burn anything down.”

Huston’s guilty plea came as a surprise to prosecutor Jane Bissert, who said she had expected to begin jury selection in the case on Monday. While Huston faced a maximum sentence of eight years in prison, the prosecutor argued for six years and English sought four years. In settling on the lesser term, Bissert said, the judge reasoned that Huston had no prior record and likely did not intend the fire to be so destructive.

Shortly after the fire, Huston admitted to authorities and to his family members that he set it with his cigarette lighter. But he claimed that the blaze was the work of “the other person inside himself.”

Said English: “He’s a person who kind of prides himself on being responsible . . . and yet this totally irresponsible personality was involved in starting the fire, and that has been very bothersome to him.”

At a preliminary hearing last February, a Los Angeles County arson investigator testified that Huston confessed to him several hours after the fire had been extinguished.

“He said, ‘I can’t lie any more,’ ” the investigator, David Westfield, said at the time. “He had a cigarette package and a lighter. He picked up his lighter and said, ‘This is what I used.’ ”

Huston had been employed by Burns International Security Services and had been on the job for only four weeks at the time of the fire.

On the night of the fire, Huston was assigned to watch over antique cars that had been used during the filming of a Sylvester Stallone movie in an area that included a street of brownstone facades used to simulate New York and other cities. According to English, the studio used the area behind the facades as a painting workshop, and had covered it with muslin cloth.

The fire began there and spread quickly when the paint and the muslin ignited. It destroyed 20% of Universal’s exterior sets, including those that had been used to film the movies “Dick Tracy” and “Back to the Future.” The studio’s King Kong exhibit, an attraction on its public tour, also was damaged.