A man charged with starting one of the wildfires in Spokane, Wash., that have destroyed hundreds of buildings planned the crime for weeks and researched when the weather would be best for igniting it, police said.

Officials have estimated the blazes in the Spokane area have burned down more than 700 structures. As of Monday afternoon, they’d burned through more than 8,000 acres.

The suspect was arrested in connection with one of three wildfires in Spokane, Wash., that have destroyed hundreds of homes and displaced nearly a quarter of the city's residents.