Police say that a man who bystanders restrained after they saw him set several fires at Lee County wildlife preserve last week was a firefighter.

Trent Schaefer, 21, allegedly started the blaze that spread to 700 acres at the Green River State Wildlife Management Area, according to NBC Chicago.

Schaefer, a volunteer firefighter in Ohio, IL, was seen getting out of his car and starting several fires around the preserve as winds gusted to 30 mph Friday. Officials said there was a high risk of brush fires that day to the weather.

Lee County sheriff’s deputies arrived and took Schaefer into custody while multiple fire companies responded to battle the blaze for hours.

 Schaefer was charged with a single count of arson.

The Illinois State Police were called to assist with the investigation because officials believe Schaefer may have set other fires in Lee County.