KGOU

Doug Williams

Doug Williams examines a polygraph test on his computer.
Jacob McCleland / KGOU

A former Oklahoma City police officer faces federal witness tampering and mail fraud charges for teaching people how to pass the polygraph test. Doug Williams was indicted last year after an undercover sting operation and his trial begins Tuesday in the Western District of Oklahoma Federal Court.

Williams meets clients at his tiny, spartan rented basement office on Main Street in Norman, where he charges $1,000 for one-on-one training sessions.