Oroville man allegedly threw firework out of car window, starting destructive Thompson fire

A 26-year-old man has been arrested and charged with arson in the Thompson fire, which torched 3,789 acres in the Northern California town of Oroville in early July.

Spencer Grant Anderson, an Oroville resident, was arrested in Chico on Thursday. He was charged Monday with arson of an inhabited structure, arson of forest land and arson causing multiple structures to burn, according to the California Department of Forestry and Fire Protection.

The charges came after an extensive 50-day investigation by a team of Cal Fire investigators brought in from around the state. At any given time, four to six investigators had Anderson under 24/7 surveillance while others conducted a forensic investigation at the intersection of Cherokee and Thompson Flat roads, the site where the fire started, Cal Fire said.

Hours into the investigation, the team concluded that the fire was likely caused by a flaming object thrown from a Toyota sedan. By July 3, a day after the fire started, they linked the car to Anderson using license plate readers.

After he was arrested, Anderson admitted that he had purchased fireworks the day the fire started and drove to Cherokee Road to test one by throwing it out the window, Cal Fire said.

The fire started on a “red flag day” — when the potential for a fast-moving brush fire was extremely high. The temperature was over 100, humidity was low, and winds were blowing west to east.

The fire traveled more than 3.5 miles, destroying 13 homes and damaging 34 structures.

Anderson could face 21 years in prison if convicted on all charges. He’s being held without bail in Butte County Jail and will be back in court on Wednesday to set dates for his plea and pretrial hearings.

Oroville sits about 20 miles south of Paradise, where the deadliest wildfire in California history, the Camp fire, killed 85 people in 2018.

Tens of thousands of Butte County residents were placed under mandatory evacuation orders after the Thompson fire started on July 2, including some who had previously lost homes in the Camp fire.