http://reason.com/archives/2016/03/31/clinton-investigation-dangerous-phase
The exception is Bryan Pagliano, the one member of Clinton's inner circle who, with either a written promise of non-prosecution or an order of immunity from a federal judge, began to cooperate with federal prosecutors last fall.
Pagliano has explained to federal prosecutors the who, what, when, how and why he migrated an open State Department email stream and a secret State Department email stream from government computers to Clinton's secret server in her home in Chappaqua, New York. He has told them that Clinton paid him $5,000 for his services.
He has also told some of the FBI agents assigned to this case that Clinton herself was repeatedly told by her own State Department information technology experts and their colleagues at the National Security Agency that her persistent use of an off-the-shelf BlackBerry was neither an effective nor an acceptable means of receiving, transmitting or safeguarding state secrets. Little did they know how reckless she was with government secrets, as none were apparently then aware of her use of a non-secure secret server in Chappaqua for all of her email uses.
We know that the acquisition and corroboration phase of the investigation has been completed because the prosecutors have begun to ask Clinton's top aides during her time as secretary of state to come in for interviews. This is a delicate and dangerous phase for the aides, all of whom have engaged counsel to represent them.
Here are the dangers.
The Department of Justice (DOJ) will not reveal to the aides or their lawyers what it knows about the case or what evidence of criminal wrongdoing, if any, it has acquired on each of them. Hence, if they submit to an FBI interview, they will go in "blind." By going in blind, the aides run the risk of getting caught in a "perjury trap." Though not under oath, they could be trapped into lying by astute prosecutors and aggressive FBI agents, as it is a crime—the equivalent of perjury—to lie to them or materially mislead them.
For this reason, most white-collar criminal defense lawyers will not permit their clients to be interviewed by any prosecutors or FBI agents. Martha Stewart's lawyers failed to give her that advice, and she went to prison for one lie told in one conversation with one FBI agent.
After interviewing any Clinton aides who choose to be interviewed, the DOJ personnel on the case will move their investigation into its final phase, in which they will ask Clinton herself whether she wishes to speak with them. The prosecutors will basically tell her lawyers that they have evidence of the criminal behavior of their client and that before they present it to a grand jury, they want to afford Clinton an opportunity blindly to challenge it.
This will be a moment she must devoutly wish would pass from her, as she will face a damned-if-you-do, damned-if-you-don't dilemma.
Here is her dilemma.
If she were to talk to federal prosecutors and FBI agents, they would catch her in many inconsistencies, as she has spoken with great deception in public about this case.
...
Some Democrats who now understand the gravity of the case against Clinton have taken to arguing lately that the feds should establish a different and higher bar—a novel and unknown requirement for a greater quantum of evidence and proof of a heavier degree of harm—before Clinton can be prosecuted. They have suggested this merely because she is the likely Democratic presidential nominee.