The Rocky Mount, N.C., tobacco farmer who drove his tractor into a shallow pond in Washington, D.C. and shut down traffic in the nation's capital in March was convicted of making a false threat to detonate explosives and destruction of federal property.

Dwight Ware Watson, 51, drove his tractor into a shallow pond on the National Mall March 17. That caused a 47-hour police standoff and backed up traffic in downtown Washington and northern Virginia.

A pre-sentencing hearing was set for Dec. 9, with sentencing on Dec. 16. Watson faces a maximum of 20 years in prison.

Watson had abandoned plans to act as his own attorney. Watson was represented by an assistant federal public defender who told jurors that his guiding principles were protecting people and standing up for his beliefs.

Watson told jurors that he was engaged in “civil disobedience” against the use of pesticides and that he told police he had an “organophosphate bomb” in a box. It turned out to be two aerosol cans of Raid insecticide, according to published reports.