Donald Gates at the federal courthouse in Washington, D.C., this month. (Astrid Riecken/For The Washington Post)

THE DISTRICT of Columbia’s agreement to pay $16.65 million to settle the federal civil rights lawsuit of a man who spent 27 years in prison for a crime he did not commit should not be the end of this troubling case. That a jury found there to be egregious police misconduct demands rigorous review of other cases handled by the detectives involved, to ensure there haven’t been similar miscarriages of justice. Also needed is resolve by prosecutors and others in the criminal justice system to tackle the systemic issues that contribute to wrongful convictions.

Donald E. Gates, 64, wrongly imprisoned for the 1981 rape and murder of a college student, reached the settlement with the city a day after a jury found he had been framed by two D.C. homicide detectives, now retired. A confession supposedly made by Mr. Gates to a police informant had, the jury determined, been fabricated, and exculpatory information was improperly withheld from his defense. It was that false confession — supplied by an informant known by police to be “treacherous” and unreliable — along with bogus hair analysis from the FBI that formed the basis for Mr. Gates’s conviction; DNA testing later exonerated him in the death of Catherine Schilling.

Just as the U.S. Attorney’s Office ordered wide-ranging reinvestigation of defendants convicted with the use of flawed FBI hair matches after the problems became apparent, so must it review other homicide cases investigated by the detectives implicated in the Gates case. Testimony revealed not only that Ronald S. Taylor and Norman Brooks exhibited tunnel vision that fixated on Mr. Gates as a suspect to the exclusion of others (which would have been bad enough), but also that they actively conspired to deprive him of his constitutional rights. Mr. Taylor was one of two top detectives in the homicide unit and, according to his testimony in Mr. Gates’s case, handled hundreds of cases. More reason for U.S. Attorney Channing D. Phillips to order an audit of their work.

In addition, we hope the outcome of this case — which underscored long-held and well-documented concerns about the reliability of government informants — gives pause to police and prosecutors and prompts them to put in place protections that guard against the problems that lead to wrongful convictions. Most needed are changes giving defense attorneys fuller information, so that if there are mistakes, it doesn’t take 27 years to uncover them.