By Judge Andrew P. Napolitano

Late last week, the inspector general of the State Department completed a yearlong investigation into the use by Hillary Clinton of a private email server for all of her official government email as secretary of state. The investigation was launched when information technology officials at the State Department under Secretary of State John Kerry learned that Clinton paid an aide to migrate her public and secret State Department email streams away from their secured government venues and onto her own, non-secure server, which was stored in her home.

The migration of the secret email stream most likely constituted the crime of espionage — the failure to secure and preserve the secrecy of confidential, secret or top-secret materials.

The inspector general interviewed Clinton's three immediate predecessors — Madeleine Albright, Colin Powell and Condoleezza Rice — and their former aides about their email practices. He learned that none of them used emails as extensively as Clinton, none used a private server and, though Powell and Rice occasionally replied to government emails using private accounts, none used a private account when dealing with state secrets.

Clinton and her former aides declined to cooperate with the inspector general, notwithstanding her oft-stated claim that she "can't wait" to meet with officials and clear the air about her emails.

The inspector general's report is damning to Clinton. It refutes every defense she has offered to the allegation that she mishandled state secrets. It revealed an email that hadn't been publicly made known showing Clinton's state of mind. And it paints a picture of a self-isolated secretary of state stubbornly refusing to comply with federal law for venal reasons; she simply did not want to be held accountable for her official behavior.

The report rejects Clinton's argument that her use of a private server "was allowed." The report makes clear that it was not allowed, nor did she seek permission to use it. She did not inform the FBI, which had tutored her on the lawful handling of state secrets, and she did not inform her own State Department IT folks.

The report also makes clear that had she sought permission to use her own server as the instrument through which all of her email traffic passed, such a request would have been flatly denied.

In addition, the report rejects her argument — already debunked by the director of the FBI — that the FBI is merely conducting a security review of the State Department's email storage and usage policies rather than a criminal investigation of her. The FBI does not conduct security reviews. The inspector general does. This report is the result of that review, and Clinton flunked it, as it reveals that she refused to comply with the same State Department storage and transparency regulations she was enforcing against others.

Here is what is new publicly: When her private server was down and her BlackBerry immobilized for days at a time, she refused to use a government-issued BlackBerry because of her fear of the Freedom of Information Act. She preferred to go dark, or back to the 19th-century technology of having documents read aloud to her.

This report continues the cascade of legal misery that has befallen her in the past eight months. The State Department she once headed has rejected all of her arguments. Two federal judges have ordered her aides to testify about a conspiracy in her office to evade federal laws. She now awaits an interrogation by impatient FBI agents, which will take place soon after the New Jersey and California primaries next week. Her legal status can only be described as grave or worse than grave.

We know that Clinton's own camp finally recognizes just how dangerous this email controversy has become for her. Over the Memorial Day weekend, John Podesta, the chairman of Clinton's campaign, sent an email to her most important donors. In it, he recognizes the need to arm the donors with talking points to address Clinton's rapidly deteriorating support with Democratic primary voters.

The Podesta email suggests attempting to minimize Clinton's use of her private server by comparing it to Powell's occasional use of his personal email account. This is a risky and faulty comparison. None of Powell's emails from his private account — only two or three dozen — contained matters that were confidential, secret or top-secret.

Clinton diverted all of her email traffic to her private server — some 66,000 emails, about 2,200 of which contained state secrets. Moreover, Powell never used his own server, nor is he presently seeking to become the chief federal law enforcement officer in the land.

The inspector general who wrote the report was nominated by President Barack Obama and confirmed by the Senate in 2013, after Clinton left office. He did a commendable job — one so thorough and enlightening that it has highlighted the important role that inspectors general play in government today.

Today every department in the executive branch has, by law, an inspector general in place who has the authority to investigate the department — keeping officials' feet to the fire by exposing failure to comply with federal law.

If you are curious as to why the inspector general of the State Department during Clinton's years as secretary did not discover all of Clinton's lawbreaking while she was doing it, the answer will alarm but probably not surprise you.

There was no inspector general at the State Department during Clinton's tenure as secretary — a state of affairs unique in modern history; and she knew that. How much more knowledge of her manipulations will the Justice Department tolerate before enforcing the law?

A graduate of Princeton University and the University of Notre Dame Law School, Judge Andrew P. Napolitano is the youngest life-tenured Superior Court judge in the history of the State of New Jersey. He sat on the bench from 1987 to 1995, during which time he presided over 150 jury trials and thousands of motions, sentencings and hearings. He taught constitutional law at Seton Hall Law School for 11 years, and he returned to private practice in 1995. Judge Napolitano began television work in the same year.