WAS HILLARY CLINTON, as secretary of state, careless with classified information that could bring harm to intelligence sources or otherwise benefit U.S. adversaries, or is she being slammed by her partisan opponents over action that was not criminal and may have simply reflected a lapse in judgment? The fog was only deepened by the recent announcement that “top secret” information was found in seven email chains, covering 22 documents totaling 37 pages, in the State Department’s review of her emails for release. Since the “top secret” information will remain hidden, it is hard to know what to make of it.

As we’ve said before, Mrs. Clinton should not have stored her official business on a private computer server based in her home. It was faulty thinking, perhaps borne of her desire to keep control over the communications and long experience in the political trenches. She has since turned everything over to the State Department for screening and release. The emails in question — many of them sent to her by others — came from the unclassified systems of the government, and, we are told, did not have any markings on them that identified them as classified. So it does not seem that she knowingly or willfully mishandled anything classified. The question of intent here is crucial.

It is also the case that experts in the government may retroactively discover classified information in her inbox. This does not seem surprising — or criminal. The fact is that in government, business is not conducted in a vault. Every secretary of state is deeply enmeshed and constantly involved in matters — via documents, emails, meetings, calls — involving facts that are sensitive and classified. The material does not always have a prominent label. It is the responsibility of government officials to be good stewards of secrets, but it is unrealistic to think every word will be placed in a lockbox. Important things such as names of agents and sources must be strictly guarded, but not everything classified is at that level.

Now the Federal Bureau of Investigation is looking into it, and inevitably this casts a shadow over Mrs. Clinton’s presidential candidacy. The FBI may be attempting to determine if any foreign hackers were able to penetrate the server, which is an important question. We think it would be wrong to prejudge or interfere with this investigation. But voters deserve to know as soon as possible whether this was a lapse of judgment or something worse. They deserve to be told whether there is any reason to suspect criminal behavior. In the name of fairness, we urge FBI Director James B. Comey to do everything possible to answer the question sooner rather than later. If there was no criminal behavior, allowing suspicions and doubts to linger through a campaign year would be wrong.