ST. LOUIS (AP) — A St. Louis police officer shot and Grayson  Prestonkilled a man who had just shot another man Friday morning, about a block from City Hall in the city’s downtown.

Police said the officer saw a man shooting another man around 7:30 a.m. near the busy corner of Market and 14th streets, and shot the gunman. The man shot by the officer died at the scene. The man shot by the gunman was critically hurt, police said in a statement.

Names of the officer and the man killed were not immediately released.

The officer who fired is 42 and has been a police officer for 18 years, police said.