A prosecutor said Thursday that an auto mechanic was "a man bent on destruction" who ignited a wildfire that killed five U.S. Forest Service firefighters in 2006.

In opening statements for Raymond Lee Oyler's murder trial, Riverside County Deputy District Attorney Michael Hestrin told jurors that Oyler was a serial arsonist who set 25 blazes, including the Esperanza fire, and sometimes as many as three a day during 2006.

Hestrin said Oyler was "a man bent on destruction ... a man wanting to be so important, he unleashed disaster on five men."

Oyler, 38, has pleaded not guilty to 45 counts including murder and arson. He claimed he had been watching his 7-month-old child at home and then went to a casino when the Esperanza fire began on Oct. 26, 2006, as fierce Santa Ana winds roared through Southern California.

If convicted, he faces the death penalty.

The firefighters were overrun by a fierce fire as they defended a home in Twin Pines, a remote and rugged area about 90 miles east of Los Angeles. The fire destroyed 34 homes and 20 outbuildings, and charred more than 67 square miles.

Prosecutors said at most of the sites where fires were set, authorities found wooden matches bundled around or laid over a cigarette. The lit cigarette was a "timing device," allowing an average of 10 minutes before the matches would be sparked, Hestrin said.

He added Oyler also was tied to two fires through DNA evidence found where the blazes started.

Hestrin said that during one of the fires Oyler is suspected of starting, a camera recorded the defendant's car coming into and leaving the area. Investigators searching the vehicle found a wig, clothing and a slingshot that appeared to have burn marks on it, Hestrin said.

Fire officials had set up hidden cameras at several sites where they believed fires might erupt.

Defense attorney Mark McDonald said in his opening statements that the prosecution had neither DNA evidence nor witnesses to connect Oyler to the Esperanza fire.

"You will only hear theories," McDonald said. "This may be just hopefulness that someone will be held accountable for Esperanza."

The attorney said he would call an arson expert to testify that more than one person was likely responsible for setting the fires because different types of incendiary devices were used.

"They are not in compliance ... with someone we would call a serial arsonist," McDonald told jurors.

McDonald has been fighting to admit into evidence that a Forest Service investigation found another possible arsonist — a firefighter who worked in the area when the suspicious fires started.

Firefighters Jason McKay, 27; Jess McLean, 27; Daniel Hoover-Najera, 20; Mark Loutzenhiser, 43; and Pablo Cerda, 23, died in the fire.

The trial court was scheduled to hold a motions hearing Friday, and testimony was expected to resume Monday.