ST. LOUIS -- A 15-year-old boy was charged with killing a first-year St. Louis police officer.

The name of the suspect was not released. He is being held by juvenile authorities in Wednesday's shooting death of officer Norvelle Brown, a 22-year-old who was in his first year on the job.

Police Chief Joe Mokwa said that the 15-year-old decided on Wednesday to kill a police officer and murdered Brown "in a spur of the moment decision."

18-year-old Xavier McCully was charged with unlawful transfer of a weapon to a minor, a misdemeanor.

Xavier McCully (18) charged with unlawful transfer of a weapon to a minor, a misdemeanor

Mokwa says McCully supplied the gun and was there when Brown was shot but did not know that the 15-year-old planned to shoot an officer.

He says a third person also was at the scene of the shooting, but also did not know about the plan.

Brown was killed Wednesday night while patrolling alone on the city's north side.

He was the third St. Louis police officer shot to death in the line of duty since 2000.

Officer Brown will be laid to rest this morning at 10:00 a.m. at Lake Charles Cemetery on St. Charles Rock Road.

(Copyright 2007 by The Associated Press. All Rights Reserved.)