A well-known genetics researcher at the University of Pittsburgh, indicted for his role in obtaining biological materials for a friend's art exhibit, pleaded guilty yesterday in federal court in Buffalo, N.Y.

Robert E. Ferrell, 64, of Edgewood, entered a plea to the lesser misdemeanor charge of "mailing an injurious article," which carries a recommended guideline range of up to six months in prison and a $5,000 fine.

Originally, Dr. Ferrell was charged with four counts, including mail and wire fraud, relating to his procurement of two biological materials in late 2003 and 2004.

Dr. Ferrell was indicted in June 2004, along with Steven A. Kurtz, a former Carnegie Mellon University art professor and founding member of the Critical Art Ensemble, which uses art to examine the impact of science and technology on consumer culture.

The matter came to the attention of law enforcement on May 11, 2004, when Mr. Kurtz, who now teaches art at the State University of New York at Buffalo, awoke to find that his wife had died.

He called police, and when help arrived, officers noticed the biological materials in his home.

They called the FBI's Joint Terrorism Task Force, which arrived in full biohazard gear to search his home.

Mr. Kurtz was taken into custody and confined to a hotel room for 22 hours.

Though it turned out that Hope Kurtz died from heart failure, the government sought out a terror link.

Ultimately, prosecutors alleged that both Mr. Kurtz and Dr. Ferrell committed fraud by obtaining two bacteria, serratia marcescens and bacillus atrophaeus, from a biological supply company.

Because Mr. Kurtz could not legally obtain the materials, the government said, he asked his friend to order them.

The materials were sent to Pitt's human genetics laboratory, and Mr. Ferrell then sent them to Mr. Kurtz's home in Buffalo.

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

Mr. Kurtz planned to use them as part of an art project addressing genetically modified food. It was scheduled to open at the Massachusetts Museum of Contemporary Art within days of the raid.

According to a statement released by his family, Dr. Ferrell chose to plead to the lesser misdemeanor charge for health reasons. Since the investigation began, he has suffered two minor strokes and a major one that required months of rehabilitation. In addition, the 27-year survivor of non-Hodgkin's lymphoma underwent a stem-cell transplant.

"After 3¹/₂ years of having his life held hostage by the Department of Justice, he was left with pleading or dying," said Lucia Sommer, coordinator of a defense fund set up for Dr. Ferrell and Mr. Kurtz.

Dr. Ferrell's daughter, Gentry Chandler Ferrell, said in the statement that the plea agreement was one way for her father to eliminate some of the uncertainty in his life.

"I remain unable to wrap my mind around the absurdity of the government's pursuit of this case, and I am saddened that it has been dragged out to the point where my dad opted to settle from pure exhaustion," she said.

The charges prompted a storm of criticism in the art world, which has been organizing fund-raisers all over the world to pay for Mr. Kurtz's and Dr. Ferrell's defense.

Even though Dr. Ferrell pleaded guilty, Ms. Sommer said Mr. Kurtz is healthy enough to keep fighting.

"Steve will continue to stand on principle," she said. "He will never plead to something he didn't do. No criminal activity took place. We're still talking about $256 worth of harmless bacteria, used for educational art projects exhibited all over the world."

Mr. Kurtz's case is not scheduled for trial, but oral arguments are set for Oct. 30.

As part of his plea agreement, Dr. Ferrell said he will cooperate with the government "by providing complete and truthful information regarding his knowledge of all criminal activity, whether undertaken by the defendant or others, in any way involving or related to the procurement and distribution of biological organisms."

His attorney, Efrem M. Grail, said his client has been interviewed by the government twice.

"The truth will out; whether that helps the prosecution or defense is not a consideration in Dr. Ferrell's testimony," Mr. Grail said. "It won't color his testimony one way or the other."

Dr. Ferrell will be sentenced by U.S. District Judge Richard J. Arcara on Feb. 11. His attorney likely will ask for probation. Dr. Ferrell, who continues to teach in the Graduate School of Public Health, could be ordered to pay restitution to Pitt.

Officials there did not return a phone call seeking comment.