But Mr. Fox also said the renewed pressure by the committee had quickly persuaded witnesses to negotiate terms under which they would cooperate.

After a lengthy period on Sicily collecting testimonials, evidence and persuading witnesses to come forth, Cicero returned to Rome and won the case in a series of dramatic court battles.

The strategy centered on persuading potential witnesses to talk with investigators.

It would be difficult for the Government to persuade such witnesses to offer damaging testimony once again.

Prosecutors also struggle nationwide to persuade frightened witnesses to testify.

In the past, it has been nearly impossible to persuade Chinese witnesses to testify in court against the gangs, law-enforcement officials have said.

Among the many obstacles to mounting a case against the former dictator, the prosecution has had difficulty persuading witnesses in the trial to testify.

Mr. Walsh must ward off harassing litigation and persuade witnesses and targets to cooperate.

Those who opposed Stephen persuaded false witnesses to testify that Stephen was guilty of blasphemy against Moses and against God.

The court, often short of funds, has had trouble gathering evidence and persuading fearful witnesses to give testimony.