Rand Paul injuries remain shrouded in mystery...

BOWLING GREEN, Ky. — A man who allegedly assaulted Sen. Rand Paul (R-Ky.), breaking at least six of his ribs, pleaded not guilty to misdemeanor assault charges Thursday, and faces the possibility of much more serious federal and state felony charges as investigations continue.

A pretrial conference was set for Nov. 30 for Rene Boucher, 59, who allegedly attacked Paul in the senator’s yard on Friday.

The arraignment in Warren County district court lasted just two minutes, as he waived a formal reading of his rights. The retired pain doctor and former anesthesiologist appeared in a suit with his attorney.

[Sen. Rand Paul says he suffered six broken ribs in attack]

Rene Boucher, who has been charged with attacking Sen. Rand Paul of Kentucky pleaded not guilty to an assault charge. (Warren County Regional Jail/AP)

Warren County Attorney Amy Milliken said Boucher faces a possible 12-month sentence and $500 fine for fourth degree assault, but the prosecutor also noted that the Kentucky State Police and FBI continue to investigate more serious charges.

Milliken said her office has not spoken directly to Paul, and is instead relating information about the case to him through the FBI.

Fourth-degree assault is the most serious charge prosecuted by the Warren County Attorney.

If more serious state charges are brought against Boucher, they would be prosecuted by Commonwealth’s Attorney Christopher T. Cohron.

Stephanie Collins, a spokeswoman for the U.S. Attorney’s Office in Louisville, said Thursday morning there was no update on a potential federal prosecution of Boucher.

O’Keefe reported from Washington.