A 57-year-old man arrested in connection with an Arizona wildfire that prompted the evacuation of more than 2,000 households told police that he had burned toilet paper but didn't think it would smolder.

Matthew Riser was arrested Sunday and charged with violations of building, maintaining, attending or using a fire, campfire or stove including charcoal, coal and briquettes; occupying or using a residence on Forest Service lands and possession of a controlled substance (marijuana).

According to a probable cause statement, Riser was seen driving rapidly away from the Pipeline Fire, one of three fires burning in the Coconino National Forest.

As of Wednesday, the fire had ballooned to 20,178 acres and as of Tuesday night was 0% contained.

Riser was stopped Sunday by a Coconino County Sheriff’s Deputy who asked him if he had seen “no campfires” signs in the area. Riser said he didn't see them on the way into the park but saw them as he was leaving, the probable cause statement said. He added he was homeless and a traveler and had camped in the area for about two days.

Riser admitted to deputies that he had burned his "s--- paper" at noon on Saturday "and didn’t think it would smolder all night," court documents said. He said he placed the toilet paper under a rock after burning it, and once he saw it had ignited a fire, tried to put it out with his sleeping bag.

He also gave deputies permission to search his truck, where they found marijuana, the court documents said.

Riser had an initial court appearance on Monday. His attorney, Daniel Benjamin Kaiser, did not immediately respond to a request for comment Wednesday.

Elisha Fieldstadt is a breaking news reporter for NBC News.