An 18-year-old prison halfway house resident has been arrested in connection with the shotgun slaying Monday night of a Korean supermarket owner in Southeast Washington, D.C. police reported yesterday.

Police identified the suspect as Jimmy Robinson, who lived at the city's Halfway House 3, located at 1430 G St. NE. Robinson was serving time for unauthorized use of a car, police said.

Police also announced the arrest of a 14-year-old youth who was allegedly an accomplice in the holdup. Both Robinson, who police allege was the gunman, and the 14-year-old were charged with felony murder and presented in Superior Court and Family Court, respectively. Robinson was ordered held without bond.

A third suspect is being sought in connection with the slaying, police said.

The slain man was Chang Yol Yu, a 37-year-old microsystems engineer whose wife owned the Central Avenue Supermarket at 5575 Central Ave. SE. On Monday night, just before 8 p.m., two men entered the store and demanded money from Chang, who had stopped by the store that evening to help his wife. Chang complied with the robbers, but was shot anyway, according to police. He was pronounced dead on the scene by the D.C. medical examiner.

According to police reports, the store owners had called for police assistance on four previous occasions: once for attempted burglary, once for attempted robbery and twice for larcenies, but they had declined police offers to stake out the store.

Capt. Jimmy Wilson, head of the homicide branch, said the arrests were made as part of a new procedure that teams the efforts of homicide detectives with detectives in the districts where the crime occurred.