A convicted killer has been arrested on suspicion of deliberately igniting the largest of three catastrophic wildfires in Spokane County, Washington. Aaron Farinacci, 37, was booked into the county jail Monday on a first-degree arson charge over the Old Trails Fire. That blaze and two others have torched upward of 8,000 acres and wrecked roughly 700 buildings since Saturday. A witness reported a man crouching in grass near where the fire started, Sheriff John Nowels told a news conference. The sheriff said nothing ties him to the Autumn Lane and Fairview fires.