Norco resident Justin Wayne Halstenberg, 34, is accused of deliberately igniting the Line Fire on Sept. 5 near Baseline Road in Highland. He now faces nine felony charges and is being held without bail.
Halstenberg is charged with one count of aggravated arson, one count of arson causing great bodily injury, one count of arson of an inhabited structure or property, three counts of arson on a structure or forest land and three counts of possession of material or a device for arson. He is scheduled to be arraigned Friday.
One of the charges filed is related to a broken ankle suffered by a firefighter, and another charge is connected to residence in Running Springs that burned down, San Bernardino County District Attorney Jason Anderson said during a press conference Thursday.
The charge of aggravated arson carries a sentence of 10 years to life in prison.
Officials said they found three incendiary devices they believe Halstenburg used to start fires - the first two attempts were unsuccessful, and the third attempt led to the Line Fire.
The first fire on Bacon Lane was extinguished by firefighters, and the second blaze - just east of Bacon Lane on Baseline Road - was stomped out by a good Samaritan, according to the DA's office. The Line Fire erupted near the second blaze.
Authorities said investigators cracked the case when automatic license plate readers picked up the same vehicle in the area of all three fires around the time they started.
Tips from the public and detective work also helped investigators, officials said.
"This remains an ongoing investigation. There remains a potential for additional charges, if further damages to structures or injuries to personnel or residence are incurred," Sheriff Shannon Dicus posted on X.
Anderson said he finds arson especially "despicable" because the suspect gains nothing and families are thrown into despair running from their homes.
Cal Fire reports the Line Fire has grown to 37,207 acres and is 18% contained.
The Line Fire is burning through dense vegetation that grew after two back-to-back wet winters that included snowstorms that caused tree branches to break, leaving behind a lot of "dead and down fuel," said Cal Fire Operations Section Chief Jed Gaines. While it forced the evacuations from Running Springs, another wildfire threatened the mountain community of Wrightwood about a 50-mile (80-kilometer) drive to the west.
Firefighters battling the Line Fire and two other major wildfires took advantage of cooler weather Wednesday as they slowly gained the upper hand, but not before dozens of homes were destroyed and thousands of people were forced to evacuate.
California is only now heading into the teeth of the wildfire season but already has seen nearly three times as much acreage burn than during all of 2023. The wildfires have threatened tens of thousands of homes and other structures across Southern California since they accelerated during a triple-digit heat wave over the weekend.
No deaths have been reported, but at least a dozen people, mainly firefighters, have been treated for injuries, mostly heat-related, authorities said.
Interactive map from Cal Fire
This interactive map from Cal Fire shows the latest evacuation orders and warnings, plus road closures and detours:
This 3D map, also from Cal Fire, shows the breadth of the fire zone, and it includes the latest acreage.
The Associated Press contributed to this report.