A former U.S. Department of Homeland Security (DHS) press aide has pleaded no contest after a police sting caught him in "sexually explicit" conversations with a "teenage girl" online.

Brian J. Doyle, 55, was arrested after he had inappropriate and illegal conversations with an undercover detective posing as a young girl. Now Doyle faces up to five years behind bars, and a sentencing hearing scheduled for late November.

Outside the Polk County courthouse in Florida, Doyle told reporters, "I just want to say one thing. I am very, very sorry. Very sorry."

According to WSVN 7 in Miami, prosecutors said Doyle wrote "very graphic" descriptions of sexual acts in online chats with a 14-year-old named "Ashlynne," who was actually an undercover Polk County sheriff's detective. Doyle was arrested after detectives said he tried to set up a meeting in Florida when the girl wasn't menstruating.

At one point during the conversation, Doyle wrote that "law enforcement is very good at this ... I have soooo much to lose ... despite your denials that it was rape ... they would prosecute me. And I would go to prison."