The last time Robin C. Arnold was seen before she was slain was exactly a year ago as she plied her trade as a prostitute at the corner of 13th and N streets NW.

Six days later, her nude and severely decomposed body was found by a truck driver in a remote wooded area of Dulles International Airport in Loudoun County.

The FBI, which is handling the case, says it still has no idea who killed Arnold, who was 27 years old, and is still trying to find out.

"Somebody has to know" more details, said special agent Alan A. Malinchak of the FBI's Alexandria office. Although several people saw Arnold on the street the night of June 9, 1985, all leads so far have turned out to be dead ends, he said.

A medical examiner ruled that Arnold died either June 10 or June 11, Malinchak said. Her body was too decomposed to determine the exact cause of death.

The FBI and D.C. police officials say her slaying appears to be unrelated to the unsolved deaths of other prostitutes around the same time.

The Baltimore native had been working as a prostitute in Washington for two years to support a costly drug habit, according to friends and police.

"She'd do anything goofy, crazy," said one friend of Arnold. "She was just wild in her own little way."

Anyone with information about Arnold's death is asked to contact the FBI at 703-361-5193.