The criminal investigation of Hillary Clinton is back front and center now that the FBI has released proof that her failure to safeguard state secrets caused the secrets to fall into the hands of foreign governments, some of which wish the United States ill.

Even though the case against her — which was closed and then reopened and then closed again — is old news and she obviously is no longer a candidate to become president of the United States and has been staying below the radar for the past two months, recent developments have regenerated the case.

Here is the back story.

On July 5, FBI Director James Comey announced publicly that the FBI would recommend against seeking an indictment of Clinton for espionage — the failure to safeguard state secrets that had been entrusted to her. He argued that though the case against her was strong — as secretary of state, she had been extremely careless with secrets; exposed hundreds of materials that were confidential, secret and top-secret; and used non-secure mobile devices while in the territory of hostile governments — no reasonable prosecutor would take the case.

Why was the decision of whether to prosecute Clinton left to Comey? 

The FBI's job is to gather evidence of federal crimes and to present that evidence to career prosecutors in the Department of Justice for evaluation. The FBI has numerous investigative tools available to it. One of those tools is presenting evidence to a grand jury and requesting subpoenas from it. Another is presenting evidence to a federal judge and requesting search warrants from the judge. A third is obtaining the indictment of someone who is in the inner circle of the person who is the true target of the investigation and then persuading that indicted person to become a government witness.

None of those tools was used in the Clinton case.

As well, a major interference with the case occurred when Attorney General Loretta Lynch agreed to meet privately with former President Bill Clinton. He was — and still is — also the subject of an FBI criminal investigation. Though both Lynch and Mr. Clinton denied talking about the investigations, the attorney general took herself and senior DOJ management off the Hillary Clinton case, leaving the FBI director with the authority to decide whether to prosecute. So based on Comey's decision that no reasonable prosecutor would take the case against Mrs. Clinton, it was closed.

The case was briefly reopened 11 days before Election Day. The FBI announced it had stumbled upon a potential treasure-trove of emails contained in a laptop jointly owned and used by Hillary Clinton's closest aide, Huma Abedin, and her husband, former Rep. Anthony Weiner. The FBI believed at the time that the laptop contained nearly every email Abedin had received from Clinton. Weiner was under investigation for various sexual crimes, and the FBI had obtained the laptop in its search for evidence against him.