Minutes after one man was shot to death and another was wounded in a District Heights convenience store early yesterday, two off-duty Prince George's County police officers unwittingly stopped the suspects as they sped through a traffic light, authorities said.

As the officers, who were in uniform and a marked patrol car, were writing the traffic citation about 3 a.m. at Silver Hill Road and Pennsylvania Avenue, a description of the two men and their gray sedan was broadcast over the police radio, spokesman Mark Polk said.

The officers, corporals assigned to the Oxon Hill station, detained the men until a witness could be brought from the convenience store to identify them, Polk said.

The suspects were arrrested without incident, police said.

Timothy Dwayne Sims, 19, of the 6000 block of Eastern Avenue, Hyattsville, and James Butler Thomas, 19, of the 4200 block of East Capitol Street in the District, were jailed without bond yesterday on first-degree murder charges, police said.

Walter Wilkins, 21, of the 3000 block of Stanton Road SE, died of a gunshot wound in the head, police said. His companion, a 21-year-old District man, was reported in serious condition at Southern Maryland Hospital Center, suffering from gunshot wounds in the stomach and arm.

Police said that Sims and Thomas followed Wilkins and the 21-year-old District man from an area nightclub to a 7-Eleven store in the 6100 block of Marlboro Pike in District Heights. Once inside the store, the four began to argue. One man left and returned with a gun, firing at Wilkins and his friend as store clerks dived for cover, police said.