But the prosecutor could have learned about her through phone records and the questioning of government officials.

He had been an alternate until another juror was dismissed after prosecutors learned that that juror lived near the chief Federal agent in the case.

But prosecutors soon learned that three of them had committed suicide over the years and that another, Mark Barr, was suffering from terminal cancer.

The prosecutors soon learned that in its eagerness to move past the riots, York had given its future mayor a free pass.

"We were surprised," Mr. Sullivan said of his reaction when he and other prosecutors learned of the covert operation.

It was not until early 2002, Judge Duffy noted, that prosecutors first learned of the recordings.

In this case, prosecutors did not learn about the incident until more than two days after it occurred.

Justice Department policy requires special procedures be used in such cases to protect lawyer-client privilege and insure that prosecutors do not improperly learn of defense strategies.

But as prosecutors have learned from the Kozlowski trial and others, persuading a jury to carefully weigh complex testimony about accounting rules can be a challenge.

Over the years, prosecutors have learned that aggressiveness is rewarded.