A law-enforcement official said privately that prosecutors had expected that the woman would be found mentally disturbed and would be committed for a long-term hospital stay.

Although he is now in the hospital with self-inflicted stab wounds, prosecutors expect him to be well enough for the court appearance.

Consequently, prosecutors stated they could no longer believe Diallo beyond a reasonable doubt, and could not expect any jury to do so either.

But the official, who spoke on condition of anonymity, said that the prosecutors expected to get a week or less.

"The people who are threatened into cooperating will say whatever the prosecutors expect them to say to reduce their sentences."

But it is unclear how much she remembers and what prosecutors expect to learn from her.

In a day or so, said Mr. Williams, the spokesman for the District Attorney, prosecutors expect to go before the grand jury to present the assault charges.

Mr. Genser said that none were, suggesting that the prosecutors had not expected the ruling.

As a practical matter, neither prosecutors nor defense lawyers expect the open plea to be very rare.