FOR THE first time in more than three years, there were pictures of a smiling John Zaccaro in the papers this week. Mr. Zaccaro was acquitted by a New York jury on Wednesday of charges that he had conspired to extort a million-dollar bribe from a cable television company.

The case against Mr. Zaccaro was one of a number involving public corruption in New York City. Prosecutors alleged that in 1981 he conspired with Donald Manes, who was then president of the Borough of Queens, and Francis X. Smith, then the chief administrative judge of the State Supreme Court in Queens, to solicit a bribe from a company seeking the cable television franchise for the county. Mr. Manes resigned under fire last year and has since committed suicide; Mr. Smith was convicted of perjury in connection with these events and has been sentenced to two years in prison.

But the case against Mr. Zaccaro was weak. Like many cases involving attempted bribery -- no money was ever paid to anyone -- the prosecutor's case was built on circumstantial evidence and in particular on what was said at a meeting attended only by Mr. Zaccaro, Mr. Manes and the cable-company executive, Raymond Flynn. When Mr. Flynn, who was called as a prosecution witness, testified that he did not believe Mr. Zaccaro was trying to bribe or threaten him, only to warn him of corruption in the system, the case fell apart, and the defense rested without calling a single witness.

In the aftermath of the trial questions have been raised about the possible political motivations of the prosecutor. Mr. Zaccaro's wife, Geraldine Ferraro, has simply said that the district attorney was "dumb" to have brought the charges. But since the Zaccaros had been close personal friends not only of some of the defendants in the current scandals but of the prosecutors as well -- former representative Ferraro had worked as an assistant district attorney in the Queens prosecutor's office -- the situation was a delicate one. Paul Pickelle, the attorney who tried the case, said after the verdict that he "would much rather be explaining why we brought {the case} and lost than why we never brought it at all." Nevertheless, and without hearing a single word from the defense, it took the jury only six hours to find Mr. Zaccaro not guilty.

In retrospect, it's clear that the prosecutor had suspicions -- and they might have been reasonable ones -- but he had no evidence. Why didn't he understand this before the trial? How carefully could he have questioned his star witness if he was surprised by the testimony and was left with no case without it? It simply isn't fair to a defendant to proceed with a prosecution in order to make some kind of a record of diligence; being indicted and tried for a felony is a terrible ordeal even if the defendant is acquitted.

A public figure is entitled to no special treatment from prosecutors and courts. But he should not be viewed as a special target either. The Zaccaros have had many troubles involving family members and the law since the 1984 nomination. They should not have been put through this latest trial.