Federal court records say James Flemons and Larry Loftis bought pump sprayers to use in the arson a month before burning the building. Prosecutors said they poured gas and kerosene in the building.
Flemons reached a plea agreement in August 2011. Loftis pleaded guilty earlier this month.
Flemons sentencing is set for Feb. 27 in U.S. District Court in Aberdeen. Court records did not say when Loftis will be sentenced.