Nearly four years after it started, a legal drama for a genetics researcher at the University of Pittsburgh that at one time involved allegations of bioterrorism has finally ended -- with the minimum fine and unsupervised probation.

Dr. Robert E. Ferrell, of Edgewood, was ordered yesterday by a federal judge in New York to pay $500 and serve 12 months of unsupervised probation for helping an art professor friend obtain biological materials for an exhibit.

Dr. Ferrell's defense attorney, Efrem M. Grail, said he and his client were relieved by the sentence handed down by U.S. District Judge Richard J. Arcara of the Western District of New York.

In exchange for his plea on the reduced charge, Dr. Ferrell must cooperate with the case against his friend and former Carnegie Mellon University art professor, Steven A. Kurtz.

Mr. Kurtz, a founding member of the Critical Art Ensemble, which uses art to examine the impact of science and technology on consumer culture, asked Dr. Ferrell to obtain two biological materials for him in late 2003 and 2004, prosecutors contend.

Dr. Ferrell ordered the material and had it sent to Pitt's human genetics lab, and then forwarded it to Mr. Kurtz's home in Buffalo, N.Y.

Health officials have said the materials posed a low risk of human infection.

Mr. Kurtz said he planned to use the bacteria as part of an art project addressing genetically modified food.

On May 11, 2004, Mr. Kurtz's wife died at home. He called police, and when they arrived, they saw the biological materials. Although Mrs. Kurtz died of heart failure, the FBI's Joint Terrorism Task Force was alerted, and they showed up in full biohazard gear to search his home.

The case against Mr. Kurtz, who now teaches visual studies at the State University of New York at Buffalo, is currently on hold until Judge Arcara rules on a defense motion to dismiss the charges on the grounds that the government has not alleged a crime in the indictment.

Unlike with Dr. Ferrell, Mr. Kurtz's attorney, Paul J. Cambria Jr., said the government has not approached his client with a deal offering a reduced misdemeanor charge.

And even if it did, it's not likely Mr. Kurtz would respond.

"He's made it clear he doesn't believe he committed a crime, and I agree with him," the lawyer said.

No witnesses were called at Dr. Ferrell's sentencing. Instead, he read a brief statement, in which he said he regretted his actions and the situation that got him into court.

He also asked Judge Arcara to help put the case behind him.

Since the prosecution began, Dr. Ferrell has had three strokes and dealt twice with cancer, Mr. Grail said.

"He's in remission right now," Mr. Grail said. "He's spending some time doing science."