What's Next for the FBI's Renewed Investigation Into Clinton's Email Server

DOJ working with FBI to move as "expeditiously as possible."

Investigators are targeting work-related emails and any emails that may have gone to the private Clinton server. The FBI will use computers to eliminate any emails that it has already seen. Agents will also look at the time frame when Clinton was at the State Department but may include some time afterward, according to sources.

The FBI investigators working on the latest cache of emails are the same ones who conducted the earlier Clinton private email server probe. It's a collection of cyber and forensic experts and counterintelligence agents, numbering in the dozens. The goal was to have people most familiar with this case step back into it, said sources familiar with the investigation.

The FBI hasn't yet determined if the newly discovered emails are truly new to the bureau or whether any of them contain any sensitive information.

The emails were found as part of a separate criminal investigation as FBI agents in New York were analyzing a laptop used by Weiner, who was accused of sending sexually explicit messages to an underage girl. Since the Clinton-related emails were found while investigating another case, the FBI needed a separate warrant to examine those messages.

Federal agents discovered the emails weeks ago but presented the findings to FBI Director James Comey only last Thursday. On Friday he sent a letter to key members of Congress informing them of the update. That sparked a frenzy in the Clinton campaign and an immediate backlash against Comey, as lawmakers and former officials on both sides of the aisle demanded for a more complete understanding of the new information. It is long-standing DOJ tradition to steer clear of potentially influential investigative actions so close to an election.

On Sunday the FBI obtained the appropriate warrant and began reviewing thousands of emails.

Comey is receiving regular updates on the investigation, and if something definitive develops quickly, he might consider whether to release additional information.

"We assure you that the department will continue to work closely with the FBI and together dedicate all necessary resources and take appropriate steps as expeditiously as possible, wrote Assistant Attorney General Peter Kazik in the letter.

Ben Siegel contributed to this story.