A 43-year-old District man was convicted yesterday in the shooting death of a man who prosecutors alleged was his rival in a love triangle.

John E. Poteat was convicted of first-degree murder in the 1984 death of Wayne Carroll in the drug trafficking area of 11th and O streets NW.

Poteat's girlfriend, who prosecutors said was the focus of the love triangle, was charged with perjury after she told a D.C. Superior Court hearing commissioner that she had lied when she told a grand jury that she had witnessed Poteat shooting Carroll.

The grand jury testimony of Elaine Kelly, also known as Barbara J. Hoffman, led to Poteat's initial arrest in Carroll's death. Kelly, whose charges are still pending, did not testify at the week-long trial.

Prosecutor Terence J. Keeney argued that Poteat shot Carroll in the early morning hours of Sept. 12, 1984, out of vengeance because they shared a girlfriend and Poteat wanted to settle a score. Witnesses said they had been quarreling.

Defense attorney Russell F. Canan argued that the murder was a drug-related one committed by another person who had fought with Carroll several days earlier over drugs and money. Canan did not dispute that Poteat was involved in drugs.

Poteat must be sentenced to at least 20 years in prison without possibility of parole because he was convicted of first-degree murder.