A D.C. Superior Court jury convicted two Northwest Washington men yesterday of murdering a 42-year-old Korean woman during a robbery of her grocery store last March, which ended in an exchange of gunfire between the woman and the robbers.

Gregory Smith, 32, and Darion Willis, 20, were found guilty of first-degree murder, attempted robbery while armed and carrying a pistol without a license.

Theodore Rhem, 18, who had accompanied Smith and Willis to the store and participated in the shooting, had pleaded guilty to second-degree murder and testified for the prosecution.

Smith and Willis, cousins who lived at 1305 Columbia Rd. NW, could be sentenced to 20 years to life in prison, prosecutors in the U.S. attorney's office said.

Yun Cha, who came to this country 11 years ago with her husband and two children, was fatally shot March 8, 1985, in the Sherman Avenue Market, 3001 Sherman Ave. NW.

Smith, who had eight prior convictions, also was convicted of obstruction of justice for threatening a witness to the shooting.

Both robbers were armed with handguns and each fired at Cha and her husband, but it was bullets from Willis' gun that killed Cha, according to prosecutors. About $50 was taken in the robbery.

Cha's son said that his father recently sold the store to another Korean family because the work became too stressful for him.

"We're very pleased that the trial is over. The incident took a lot of strength out of my father," said the son, J.C. Cha, 21, a student at the University of Maryland.