An Illinois man pleaded not guilty Wednesday to federal charges he fatally shot a sheriff's deputy who was part of a U.S. Marshal's fugitive task force trying to serve an arrest warrant at a hotel.

Floyd E. Brown, 39, of Springfield appeared in Rockford federal court sitting in a wheelchair and wearing green jail scrubs. He didn't speak except to tell a judge "yes" when asked if he understood the charges against him. A grand jury on Tuesday indicted Brown on first-degree murder and weapons charges.

Brown's public defender entered not guilty pleas on Brown's behalf and then withdrew as his attorney. U.S. Magistrate Judge Iain D. Johnston then appointed two other defense attorneys qualified to handle death penalty cases to represent Brown, who faces a potential death penalty.

Brown is accused of killing 35-year-old McHenry County Sheriff's Deputy Jacob Keltner on March 7 while the task force tried to serve Brown his arrest warrant at a Rockford hotel. Police say after Brown shot Keltner he fled south in a vehicle that eventually crashed along an interstate in central Illinois. An hours-long standoff ensued that ended with Brown's arrest.

The case is next scheduled to be in court May 14.