THE CARD WAS SIGNED WITH A question mark, but Virginia Brieant found nothing suspicious about the Valentines' Day gift of Golden Godiva candy that had been sent to her Westchester County home. She unwrapped the box and ate four of the chocolates. Then she collapsed.

That evening Chief Judge Charles L. Brieant Jr. returned from work to find his wife violently ill. She was rushed to a hospital where it was determined that she had ingested atropine and sparteine, substances which induce delirium and hallucinations. For several days, her life was in danger.

Early in the federal investigation which followed, FBI agents ascertained that one person was the possible, and perhaps only, suspect. His name was Dr. John Buettner-Janusch, and once he had been one of foremost scholars in the country, a man at the top of his field and chairman of New York University's Anthropology Department.

Seven years ago Judge Brieant had sentenced Buettner-Janusch to five years in jail for manufacturing LSD and Quaaludes in his Washington Square laboratory, a facility that NYU had built specially for him.

Seven years ago, Buettner-Janusch had witnessed the end of his career as an acclaimed and highly respected anthropologist. This past February, he allegedly tried to murder the judge who sent him away. Moreover, he allegedly sent poisoned chocolates to several other former colleagues.

The 62-year-old Buettner-Janusch, whose health is reportedly poor, is presently being held in the Metropolitan Correctional Center. He is charged with the attempted murder of a federal judge and his wife, tampering with a consumer product, and mailing injurious matter. The maximum sentence for these four counts is 63 years. A date has not yet been set for the trial.

On paper, Buettner-Janusch's credentials look impeccable. He began his carrer as an associate professor at Yale, moved on to the directorship of Duke's renowned Primate Center and then to his position at NYU. He has published more than 75 research papers in scientific journals and wrote the popular anthropology text "Origins of Man." Could this great scholar, his friends and enemies are asking, truly be guilty of criminal behavior and deadly intent?

The jury is still out on that one. Accounts of Buettner-Janusch differ sharply from person to person. Those who knew him early in his career offer favorable reports and stand firmly behind his integrity. But many of his fellow workers and subordinates say he was an abrasive and temperamental boss. Some go so far as to say he was a lunatic.

Both his supporters and his detractors agree that he held strong opinions on everything from vegetables to music to people to the world. And, apparently, it was impossible for those who knew BJ, as he was called, not to have strong opinions about him.

In talks with former teachers, colleagues, friends and associates, a portrait of Buettner-Janusch emerges that offers a better understanding of his psyche, although it fails to explain fully the motives behind either his drug manufacturing or his attempts at murder.

The son of a well-to-do architect, Buettner-Janusch was raised in Wisconsin, did his undergraduate work at the University of Chicago and received his Ph.D. from the University of Michigan in 1957. He taught at Yale for seven years and, after failing to receive tenure, moved to Duke in 1965. In academic circles he built a reputation based on his studies in physical anthropology, specifically blood and genetic relationships between lemurs, apes and humans.

In his private life, the professor seemed just as successful. Married in 1950 to Vina Mallowitz, the daughter of a prominent New Orleans physician and herself a dedicated biochemist, Buettner-Janusch and his wife worked together both in the field--studying lemurs in Borneo and Madagascar--and in the laboratory. They enjoyed concerts and theater; one of Buettner-Janusch's common complaints about Duke was its isolated location.

Frances Gary, a friend of Vina's whose husband also worked at NYU, recalls that the pair "used to come to New York City [from North Carolina] every other weekend for opera, ballet, and Broadway shows. They were a very cultural couple."

When the Buettner-Januschs moved to Greenwich Village in 1973, lured by one of the highest salaries paid an NYU chairman, they entertained frequently in their Washington Square apartment. Buettner-Janusch, a gourmet cook, was well-known for serving meals of impeccable taste. Larger gatherings, guests remember, were catered and attended to by a butler and maid.

"Buettner-Janusch had a great zest for life, for all the beautiful things. Everything he did had an exaggerated, posh New York air," Gary says.