Schwarzenegger to Arsonists: 'We're Right Behind You'

California Gov. Arnold Schwarzenegger says arsonists behind fires in Southern California should beware -- investigators are on their trail.

"We already know that at least two of the fires were started intentionally," he told the media today. "And two more were of suspicious origin. I want everyone to understand that we will hunt down the people that are responsible for that, and we will arrest them. We will prosecute them to the full extent of the law.

"If I were one of the people who stated the fires," he added, "I would not sleep soundly right now, because we're right behind you. If I would be you, turn yourself in."

Having already identified at least one point of origin for the Santiago fire in Orange County, fire investigators were looking for someone who might at least be a witness -- the driver of a white Ford pickup truck with tubular chrome running boards.

"All I'm saying is this vehicle was traveling along the road at the time of the fire. We just want to talk to the driver," Orange County Fire Chief Chip Prather said.

Schwarzenegger also warned that officials are on the lookout to ensure that fire victms won't be victimized a second time -- by scam artists.

"If anyone tries to exploit this tragedy," he said. "I will make sure that the state of California will do anything possible, that you will pay that debt for the rest of your life."

Game On

Stubborn wildfires still threatened hundreds of homes in Southern California this morning, but in hard-hit San Diego, there have been signs of progress.

Grounds crews have begun painting the field at San Diego's Qualcomm Stadium because the game is on: The San Diego Chargers will play at home Sunday in a facility that had been used as an emergency shelter.

Workers bagged up blankets and cleaned up toys at the stadium -- reminders of the largest evacuation in California history, when the home of the Chargers became home to 10,000 evacuees.

"Qualcomm is a place where they could come for that immediate shock, obviously having to evacuate or if they unfortunately lost their homes," San Diego City Councilman Jim Madaffer said.

Heartbreak and Investigation

This weekend, thousands will face heartbreaking homecomings. And there are lingering problems even for those who still have a house -- no electricity, no utilities and in the community of Ramona, no water, in part because desperate homeowners left sprinklers on when they fled.

It's believed all of the heartache and devastation was caused by arson -- and the investigation has only just begun.

Wildland arson investigations involve looking for witnesses and clues, a little like reading signs in the woods to track.

"We look at this tree here, we see a lot of charring to this side of the tree," explained Thomas Derby, Los Angeles Fire Department Investigator. "And as we walk down around the tree, you see this nice clean area, right here. This side of the tree is not burned. So this tells you it came downhill."

By looking at the dirt, they may be able to tell if gasoline or another accelerant was used.

"You may find a discoloration in the dirt. Sometimes an ignitable liquid will change the color in the soil," Derby said.

And they look for some device -- part of which often survives the fire.

"That's really the most basic, the cigarette and the book of matches," he said.

Finding the device helps. Finding a witness is even better.

But arson is one of the hardest crimes to solve. Even if investigators find a suspect very often they need a witness, evidence and a confession.