Washington ? Working against the clock, special prosecutor Patrick Fitzgerald weighed criminal charges against two top presidential aides at the end of a two-year investigation that put the White House in a state of high suspense Thursday night.

Fitzgerald raced against today’s expiration of the grand jury that has been investigating the exposure of covert CIA officer Valerie Plame’s identity. Speculation flew across Washington about whom would be indicted or whether Fitzgerald would even bring criminal charges.

At the top of the list: presidential adviser Karl Rove and vice presidential chief of staff I. Lewis “Scooter” Libby. Both men put in their normal long day at the White House.

The prospect of indictments added to the woes of an administration already facing serious political problems.

Two blocks from the White House, Fitzgerald, who has been running the criminal investigation for nearly two years, was at work in his Washington office, considering his next moves in the investigation.

Rove and Libby have been advised that they could be charged with wrongdoing, possibly for false statements to the grand jury that has been hearing testimony about discussions with reporters about Plame’s identity.

Other possible charges are obstruction of justice or perjury, along with possible violations of a law barring disclosure of the identity of a covert intelligence agent.

When the investigation began two years ago, a White House spokesman checked with Rove and Libby, then assured the public that neither was involved in leaking Plame’s identity.