A former Department of Homeland Security press aide has pleaded not guilty to charges of sexually preying on a detective who was posing on the Internet as a teenage girl.

Brian J. Doyle, 55, submitted the not-guilty plea in writing and was not required to appear at his scheduled arraignment in Polk County Tuesday.

Doyle, who resigned from his job after the arrest, faces 23 felony charges, including 16 counts of sending pornographic movie clips to a minor.

Doyle was extradited from his home in Silver Spring, Md., where he was held since his April 4 arrest. After appearing in court in Polk County May 4, he was freed on $230,000 bail.

Doyle allegedly provided his government-issued office phone and cell phone numbers, showed off his department ID and may have used his official computer in the communications with an undercover Polk County sheriff's detective who was posing as the 14-year-old girl.

If convicted of all the charges, Doyle could spend the rest of his life in prison.