A man who ran a website that taught people how to cheat lie detector tests — and government background checks that use them — received a two-year prison sentence from the federal government on Tuesday.

Douglas Williams, 69, a former Oklahoma City police officer, pled guilty in May to training two undercover federal agents on how to cover up past criminal activity from the government, according to a Justice Department press release. Williams also told the officials to keep their mouths shut about the training.

He pled guilty to two counts of mail fraud and three counts of tampering with witnesses, authorities said.

His website, Polygraph.com, was an “Internet-based business through which he trained people how to conceal misconduct and other disqualifying information when submitting to polygraph examinations in connection with federal employment suitability assessments, background investigations, internal agency investigations and other proceedings,” according to the release.

Williams was apparently confident in his ability to skirt prosecution.

According to tech news site Ars Technica, an indictment (PDF) against Williams quoted the former cop as telling an undercover federal agent he hadn’t evaded “the government this long, and done such a controversial thing that I do for this long, and got away with it without any trouble whatsoever, by being a dumb ass."

He could have received 20 years in prison for his crimes, Ars Technica reported.