A Maryland truck driver is facing a charge of driving under the influence (DUI) of a controlled substance following an incident in Schuylkill County.

State police at Frackville said William T. Butler, of Temple Hills, was stopped along the Morea Road, at Interstate 81, and found to be under the influence.He was taken to the Schuylkill Medical Center-S. Jackson St., Pottsville, for a blood test. Butler was evaluated by a trooper certified as a drug recognition expert, troopers added.Butler was also charged with operating a tractor trailer rig without a valid CDL license. The DUI charge is pending the blood test results.