James Comey, Director of the FBI, testifies before the House Judiciary Committee during a hearing titled The Encryption Tightrop: Balancing Americans’ Security and Privacy, on March 1, 2016. Photo by Diego M. Radzinschi/THE NATIONAL LAW JOURNAL. (Diego M. Radzinschi)

As a former attorney general of my state, and a former United States attorney, it is perplexing for me to try to understand FBI Director James Comey’s conduct in the agency’s investigation of emails related to Democratic presidential nominee Hillary Clinton. We prosecutors lived by principles that he seems to have violated: Don’t discuss investigations, whether or not they are ongoing. Don’t volunteer evidence you haven’t charged. And don’t engage with legislators.

I had a hard-and-fast rule in both those offices I held: If an investigation the public did not know about turned up nothing chargeable, we didn’t ever talk about it. To this day there are investigations the public doesn’t know about. My standard line, which I could give in my sleep, was: “We don’t discuss investigations whether or not they are ongoing.”