AT LONG LAST, there has been a resolution of sorts in the tragic death of David A. Masters, the unarmed, nonviolent motorist who was shot and killed by a Fairfax County police officer on Route 1 in November 2009. Although cleared of criminal wrongdoing, David Scott Ziants, the officer who shot Mr. Masters, has been fired. That’s a sensible outcome, but it should not be the last word.

From the outset, the Fairfax police department has treated the incident almost exclusively as an internal matter — as if a shooting that took place in broad daylight and in view of dozens of witnesses on a busy roadway was of scant public interest. The department’s attitude raises questions about accountability and transparency within the force.

For days after the shooting, police officials said virtually nothing about the case. Officer Ziants was granted four days’ administrative leave before he consented to an interview by police. Some 18 months elapsed before Police Chief David M. Rohrer took meaningful action against Mr. Ziants. And even after he was dismissed, in early May, police managed to say nothing at all about it for almost two months.

Tellingly, most of the details about the case were disclosed by the chief prosecutor in Fairfax, Raymond F. Morrogh, not by police. The picture that emerged was of a senseless death. Mr. Masters, a 52-year-old former Green Beret who suffered from bipolar disorder, had no history of violence, though his behavior could be erratic. On the day of the shooting, he stole some flowers from a roadside planter, prompting a merchant to call police. He then disregarded officers’ commands that he pull over and stop his car — though, sitting in traffic, he could hardly get away. When his vehicle rolled slowly forward, Mr. Ziants, under the groundless impression that the car was stolen, that another officer had been struck and that Mr. Masters might be reaching for a gun, opened fire.

Chief Rohrer says that now that his department’s internal review is finished, he intends to apologize to the Masters family. That’s appropriate and constructive. Nonetheless, questions remain about the police department’s inexplicably slow response. With good reason, the case has prompted calls for a new method to conduct independent, outside reviews of questionable police actions, particularly in cases with tragic or lethal results.

One proposal, advanced by a group of county residents, is to establish a citizens oversight board to review such cases and report directly to the county Board of Supervisors. So far, though, both the police and Anthony H. Griffin, the Fairfax County executive, have balked at such a mechanism, even though similar ones have been effective in many parts of the country.

Mr. Griffin has said he prefers empowering an internal auditor to review allegations of misconduct. But the auditor, a county employee who, like the police, already reports to Mr. Griffin, would lack the requisite distance to give his reviews credibility. If the Masters case has shown anything, it is that the police should be subject to a genuinely independent review that is responsible, careful and judicious.