An 18-year-old man was arrested by D.C. police last night in the holdup of a Prince George's County jewelry store earlier this month in which another robbery suspect was shot and fatally injured by an off-duty D.C. police officer.

Police said Mark A. Bowman of 1809 Monroe St. NE was arrested about 8:45 p.m. at a house in the 400 block of Rhode Island Avenue NE. Bowman was charged in a warrant with armed robbery in Prince George's County after the Feb. 12 holdup at the Seabrook Jewelry and Foto Center at 9432 Lanham-Severn Rd.

During the robbery, in which two men forced a store clerk into a rear office at gunpoint, D.C. police Detective Richard Ragsdale walked into the store to purchase a gift, became suspicious and went to the rear of the store to search for the clerk, police said.

When confronted by one of the holdup men, Ragsdale drew his revolver and exchanged shots with him, hitting the man in the left side of the chest, police said. Ragsdale was grazed on his right side. The second robber fled from the store.

The wounded suspect, Walter Harris Terry, 19, of 3426 Dix St. NE, died about four hours later. Ragsdale was treated at a hospital and released.

Police said Bowman is scheduled to appear in D.C. Superior Court today for an extradition hearing.