CHESTERFIELD • A Chesterfield police officer used a secret camera to take close-up video images of a teenage boy's genitals while he detained and searched the boy, authorities say.

That is the latest allegation in the case against David Cerna, who was fired from the Chesterfield Police Department after six years on the job. A St. Louis County grand jury handed down its indictment this week. An arraignment on the new charges is set for Oct. 22.

Cerna, 33, was charged back in June with invasion of privacy in St. Louis and St. Charles counties. Authorities say he had installed a camera in a men's restroom at a gas station and lured anonymous sex partners to his home through Craigslist ads.

Then, this most recent round of allegations surfaced, involving the teen boy and other male victims. He was charged in August with sexual exploitation of a minor and second-degree invasion of privacy of multiple people, and the grand jury's indictment was filed Wednesday.