An off-duty D.C. police officer who interrupted an alleged robbery attempt yesterday shot and killed a 19-year-old man during an exchange of gunfire near a bus stop in Northeast, police reported.

Leonard Briscoe of 1553 Anacostia Ave. NE, died at Capitol Hill Hospital shortly after the 4 a.m. incident involving officer Donald Bell, 29, a 10-year veteran on the force who worked out of the 5th District.

Briscoe died of a bullet wound in the neck. Two other men were arrested in the series of events, police said.

According to police officials, the shooting took place near a bus stop at Eighth and H streets NE, outside a 24-hour convenience store where officer Bell, according to police sources, was working as a clerk.

Officials said that about 4 a.m., a man identified by police as Forest Lee Jackson, 24, of an unknown address, entered the store and approached Bell, complaining he had just been robbed at gunpoint near the bus stop.

Bell, who was not in uniform, left the store, police said, and found an unidentified man being robbed.

Police said Bell, identifying himself as a police officer, interrupted the robbery and tried to arrest the suspected robber. Bell drew his gun and struggled with the man, police said. The suspect broke free and Bell exchanged shots with him.

Police said the suspect jumped into a car with two other men. Bell posted a police lookout for the vehicle and it was spotted a short time later by police outside Capitol Hill Hospital.

There, police arrested Maurice Alonzo Briscoe, 20, also of 1553 Anacostia Ave. NE, and Irvin Joseph Jones, 21, of 1606 Kenilworth Ave. NE. Both men were charged with armed robbery.

Bell has been placed on routine administrative leave pending an investigation.

According to Thomas J. Tague, president of the Fraternal Order of Police, D.C. police officers may hold second jobs, such as store clerks, in the city but cannot be security guards.

Police are required to carry their service revolvers and respond to suspected crimes.