It’s a plain fact that inappropriate testimony by Honolulu Police Chief Louis Kealoha caused a mistrial in a federal case involving his family. What is in question is whether the chief’s lapse on the witness stand was inadvertent, or whether he intentionally sabotaged the proceedings.

This matter should not be left to speculation. The Honolulu Police Commission, which just last month reaffirmed Kealoha as head of the nation’s 20th-largest police department, must step in now, having missed earlier opportunities to insist that Kealoha be publicly forthcoming about a family dispute that has landed in federal court and spawned a civil lawsuit.

The commission owes it to the people of Honolulu to do its duty and uphold the integrity of HPD by demanding that Kealoha explain his actions, and to stand ready to take disciplinary action if those explanations are not satisfactory.

The chief leads a department of about 1,930 sworn officers and 463 civilian personnel and must be held to the very highest standards, befitting the grave authority of his job and of the position he holds as a role model for the department and the broader community.

The messy disputes pit Kealoha and his wife, Katherine, who is on personal leave as head of the Honolulu prosecutor’s career criminal unit, against Katherine’s uncle, Gerard Puana, who accuses her of stealing money from him and his 95-year-old mother, Katherine’s grandmother. Katherine Kealoha denies the accusation. Puana’s civil lawsuit against her is proceeding in state court.

Meanwhile, in federal court, Puana was on trial for allegedly stealing the Kealohas’ mailbox in 2013. The police chief, the prosecution’s second witness, brought the proceedings to a screeching halt the first day by offering unsolicited, unpermitted testimony about the defendant’s criminal history — an obvious transgression. This cannot be dismissed as a rookie mistake. Kealoha is a 31-year veteran of HPD who has been chief since 2009. He should know basic rules of evidence and testimony.

Puana’s public defender, Alexander Silvert, who objected to Kealoha’s testimony and was granted a mistrial, insists that Kealoha does know the rules. Silvert asserts that Kealoha intentionally scuttled the trial to protect his wife, whose career may be at stake if she loses the upcoming civil lawsuit. "A not-guilty verdict in this case would have gone a long way in clearing Mr. Puana’s name in helping his case against the chief of police’s wife, Katherine Kealoha," Silvert told The Associated Press. A new trial in the mailbox case is set for May, while the civil lawsuit is scheduled to go to trial next month.

No one wants to imagine such high-ranking public officials, Honolulu’s law enforcement power couple, embroiled in such problems. To be sure, Louis and Katherine Kealoha maintain that they are the victims here, robbed and falsely accused. Silvert sees it much differently, promising in his opening statement that the case would expose police misconduct, and calling in the mistrial’s aftermath for police commissioners, ethics officials and state lawmakers to investigate.

The Honolulu Police Commission is the natural place to start, and Chief Kealoha’s testimony demands an explanation. While the Kealohas are the focus of this dispute, theirs are not the only reputations being sullied. All of HPD suffers in this sour spotlight.