A man charged with starting a wildfire in Spokane, Washington, confessed to the crime, describing how he planned it for weeks and created a device to ignite a blaze that destroyed hundreds of buildings, police said.

Aaron Farinacci researched the weather to predict a day that would have “high winds, low humidity, sort of high heat” for the Old Trails Fire, Spokane County Detective Michael Drapeau said in a court filing Wednesday.

Farinacci also looked up the work of a well-known serial arsonist and purchased items to make a “time delay device” for igniting a wildfire, using notebook paper, matches, a cigarette and a rubber band, the detective said.

Drapeau said Farinacci told him that “fire is powerful, beautiful, and that things that go through fire experience a kind of rebirth.”

Farinacci is charged with starting one of three fires in the Spokane area that have burned more than 850 homes and forced the evacuation of tens of thousands of people. He’s due in court Thursday for arraignment on a first-degree arson charge. His attorney, Colin Charbonneau, did not not immediately return messages seeking comment.

Farinacci picked Saturday, Aug. 1, to start the fire because he knew there would be strong winds — reaching 50 mph (80 kph), the detective said.

He said he knew it “‘was gonna get bad,’” the detective said, but Farinacci claimed he didn’t intend it to grow as much as it did.

Paul Child, 64, has been credited with leading police to Farinacci. He was driving with his grandson along some railroad tracks when he saw a man standing there and looking toward nearby trees. About 10 minutes later, the man was still there.

“He was bent over in the brush, acting nervous,” Child told The Associated Press on Tuesday. “You get the feeling this guy’s up to something.”

“No longer than 10 minutes after I got home, my daughter says, ‘There’s a fire,’” Child recalled. “My first words were, ‘That SOB started a fire!’ It was the exact spot where he was standing.”