Last Monday Fred Williams, a District of Columbia special police officer who is empowered to carry a gun on duty and to and from work, received a subpoena to appear before U.S. attorneys as a witness in a complaint.

Williams went to court, his gun still strapped to his waist, and gave his eyewitness account. The complaint was dismissed, but a prosecutor then had Williams arrested for carrying a pistol without a license.

Williams, who is head of security at the city's Martin Luther King library, is to be arraigned in D.C. Superior Court Sept. 17.

Prosecutors have declined to comment on the case. Williams' attorney, Barry Stiller, said he is dumbfounded. "What was he supposed to do with his gun?" Stiller said. "It was safest on his hip."

Williams, 36, who has been a special police officer for 13 years, says his commission to carry a weapon has been suspended. He is continuing to work, but says he no longer has the power of arrest.

Williams said he was summoned to the U.S. Attorney's Citizens Complaint Center at 515 Fifth St. NW while he was setting up security for a mayoral candidate's forum at the library Monday night. He said he only expected to be away for an hour and was communicating with his men through a walkie-talkie while he waited for a hearing on the complaint to begin.

The complaint, over a dispute in a liquor store, was heard and dismissed by Assistant U.S. Attorney Beverly Perdue, who then had Williams arrested.