By Malcolm Gladwell
Washington Post Staff Writer
Tuesday, July 14, 1992 ; Page A03

In a unexpected twist to the science fraud scandal that has become known as "the Baltimore affair," federal prosecutors said yesterday they will cease all investigations of alleged criminal misconduct surrounding a 1986 scientific paper co-written by a Tufts University researcher and Nobel Prize-winning biologist David Baltimore.

Immediately following the announcement, Baltimore, who last year at the height of the controversy asked that the disputed paper be retracted, said that he will now take the unusual step of "unretracting" the paper.

The developments appear to change dramatically the complexion of the Baltimore case, which to date has prompted two university reviews, numerous congressional hearings, two lengthy National Institutes of Health investigations and a national debate about how science should be policed.

From the beginning, the focus of the case was laboratory research related to the immune system that was conducted by Baltimore's collaborator, Thereza Imanishi-Kari. Last March, drawing heavily on an analysis of Imanishi-Kari's notebooks by forensic experts at the Secret Service, a draft report of the NIH's science fraud unit found numerous irregularities in her research notes.

Imanishi-Kari, the draft said, "repeatedly presented false and misleading information to the NIH" and "falsified" a "substantial" portion of her laboratory work during the writing of the paper, which appeared in the scientific journal Cell.

Although the report did not find that Baltimore had personally committed misconduct, it said that his persistent defense of the paper was "deeply troubling."

The question of whether Imanishi-Kari had falsified data was then referred to the U.S. attorney's office in Baltimore for evaluation.

Baltimore and Imanishi-Kari's attorney said yesterday that new evidence produced in the past few months significantly undermined the credibility of the Secret Service's analysis.

Imanishi-Kari's attorney, Bruce Singall, said the new evidence "demonstrates that there has been no fraud, no wrongdoing, and that this matter has been a tragic mistake from the very beginning."

"I feel vindicated," said Baltimore, who has been dogged by the scandal for the past five years and last year was pressured to resign from his post as head of Rockefeller University in New York City because of his assocation with the investigation.

Baltimore said the "important question" was whether Imanishi-Kari, who has had her federal grants suspended and is still the subject of an ongoing and separate NIH ethics investigation, will be "reinstated as a respected member of the scientific community."

But Richard D. Bennett, U.S. attorney for the District of Maryland, cautioned that the decision of his office should not be taken as "a certification of any research conducted by Imanishi-Kari." Instead, he said, it was predicated on strictly legal considerations that "we were not confident that we could prove guilt beyond a reasonable doubt in a courtroom" and that "disputes on the accuracy of the scientific data compiled by Imanishi-Kari" were better handled by the scientific community.

Rep. John D. Dingell (D-Mich.), whose House Energy and Commerce oversight subcommittee has pushed heavily for an investigation of Baltimore and Imanishi-Kari from the beginning, said yesterday that "the decision not to prosecute does not change the fact that the Cell paper was retracted because of serious and extensive irregularities."

The article purported to make a critical contribution to the understanding of the human immune system. Doubts were raised about the paper almost immediately after publication by Margot O'Toole, a researcher in Imanishi-Kari's laboratory. Over the next few years, the paper was the subject of repeated inquiries and investigations, all of which found no evidence of wrongdoing by Baltimore or Imanishi-Kari.

Things changed dramatically, however, when at the request of Dingell's committee Secret Service forensic experts analyzed the notebooks that Imanishi-Kari said were the basis of the research she described in the Cell paper. Approximately 20 percent of the data, the Secret Service said, were faked, and key printouts of data that Imanishi-Kari said had been produced in 1985 when she was working on her paper actually came from someone else's research in the early 1980s.

Scientists on the panel that reviewed the NIH's case against Imanishi-Kari say the Secret Service's findings were critical in the decision to find her guilty of misconduct. Baltimore said the report also was critical in his decision to retract the 1986 paper.

But last spring, for the first time, a copy of the Secret Service's analysis was given to Imanishi-Kari's lawyers, who provided it to an independent forensic scientist, Albert Lyter.

"There are serious flaws which permeate the Secret Service reports . . . which undermine their conclusions," Lyter wrote in a highly critical 14-page affidavit submitted to the U.S. attorney's office in late June.

Lyter said that the Secret Service's conclusion that Imanishi-Kari had lifted data from other experiments was based on a faulty and misleading use of forensic techniques.

Articles appear as they were originally printed in The Washington Post and may not include subsequent corrections.