IN LAKE ELSINORE I'M RACHEL MENITOFF SHARE MY COME BACK TO THE STUDIO RACHEL THANK YOU AND ARSON SUSPECT IS IN CUSTODY TONIGHT ACCUSED OF INTENTIONALLY SETTING THE MASSIVE LINE FIRE. >> THAT IS STILL BURNING OUT OF CONTROL IN SAN BERNARDINO COUNTY TONIGHT THE LINE FIRE HAS BURNED 36,000 ACRES. IT IS 18% CONTAINED TONIGHT WITH EVACUATION ORDERS AND WARNINGS STILL IN EFFECT KTLA. SANDRA MITCHELL IS LIVE IN HIGHLAND WHERE THE LINE FIRE BEGAN AND HAS MORE ON THE ARSON SUSPECT IN CUSTODY. >> SAND. >> SHARED BY KATE IS HARD TO IMAGINE THAT ONE PERSON HAS CAUSED SO MUCH DESTRUCTION IF YOU TAKE A LOOK BEHIND US BLACKENED HILLSIDE THAT IS THE EXACT SPOT WHERE THE LINE FIRE STARTED NOW TONIGHT INVESTIGATORS NOT REALLY TALKING ABOUT A MOTIVE FOR THIS ARSON SUSPECT OR WHAT SORT OF DEVICE HE USED TO START THE FIRE. BUT THEY DO SAY THEY HAVE EVIDENCE. NEW EVACUATIONS ALL THE WAY TO BIG BEAR TONIGHT IS THE LINE FIRE BURNS OUT OF CONTROL IN THE SAN BERNARDINO MOUNTAINS AND NOW WE'RE LEARNING MORE ABOUT THE MAN ACCUSED OF INTENTIONALLY STARTING THE FIRE PUTTING PROPERTY AND PEOPLE AT RISK. >> ABLE TO LOOK AT SEVERAL DIFFERENT VIDEOS AND DETERMINE WHO THE SUSPECT WAS INVESTIGATORS SAY THEY USED AUTOMATED LICENSE PLATE READERS NEAR THE SCENE WHERE THE FIRE STARTED AND TRACKED THE SUSPECTED ARSONIST TO HIS HOME IN NORCO 35 MILES FROM THE POINT OF ORIGIN. >> CALM QUIET GUY HE WAS NO ONE EVER THOUGHT DO LIKE THAT TONIGHT 34 YEAR-OLD JUSTIN HOLSTON BERG IS UNDER ARREST FOR SUSPICION OF ARSON ARSON OF FORCE PROPERTY AND POSSESSION OF AN INCENDIARY DEVICE. >> INVESTIGATORS SERVED A SEARCH WARRANT AT THE SUSPECT'S HOUSE AND SAY THE EVIDENCE SHOWS HE COULD BE A SERIAL ARSONIST. >> IT'S MY BELIEF THAT AS TIME GOES ON WE ALLOWED TO DO THE CRITICAL WORK THAT THEY'RE DOING THAT WE'LL ACTUALLY FIND OUT THE SUSPECT MAY HAVE BEEN RESPONSIBLE FOR OTHER FIRES. >> THOSE WHO KNOW HOLSTON BERG ARE STUNNED THAT SHOCKS ME RIGHT NOW. EVERYBODY WOULD BEEN WANT TO START A FIRE. >> TONIGHT THE LINE FIRE HAS RIPPED THROUGH MORE THAN 50 SQUARE MILES FOREST 65,000 TO EVACUATED MOUNTAIN COMMUNITIES ANGELES OAKS FOREST FALLS RUNNING SPRINGS AND RIGHT AFTER A TERRIFYING EVACUATION, BROOKE, HELEN CHARLES LOST HER HOME ON PINE CONE DRIVE IN RUNNING SPRINGS. THERE IS ALMOST NOTHING LEFT. >> IT'S JUST REALLY IT HAPPENED REALLY FAST. WE WEREN'T ABLE TO GRAB MUCH. BEFORE WE LEFT AND SO YOU KNOW I HAVE ABOUT 3 TEMPER ERRORS. >> SO MUCH DAMAGE INVESTIGATORS SAY STARTED BY ONE MAN. >> IT'S JUST HEARTBREAKING. IT'S JUST REALLY HEARTBREAKING. >> BEFORE HIS ARREST. WE HAVE LEARNED TONIGHT THAT THE SUSPECT WAS A FEDEX DELIVERY DRIVER HE IS NO LONGER EMPLOYED THERE AND HE'S BEING HELD ON $80,000 BAIL