From the story here:
The arson suspect is Jesus Fabian Gonzales, 29, Sgt. Spencer Crum, a spokesman for the Sonoma County Sheriff's Office told CNBC. Crum described him as "a transient out of Sonoma" and said the suspect was "arrested for setting a small fire in a park in Sonoma on Sunday."
Speaking at the Tuesday afternoon press conference, Giordano said the arson suspect was seen "walking away from a small fire" and stopped by deputies. Also, the suspect allegedly had "a fire extinguisher and a lighter with him," said the sheriff.
Giordano said the suspect was asked whether he started the fire and responded that "he started the fire to warm himself up — something to that effect."