In courtrooms across the country, prospective jurors are being insulted regularly by defense attorneys who are asking that pretrial hearings be closed in criminal cases.

The defense attorneys do not seem to trust the citizens who might be called as jurors when the case finally gets to trial a few months later. They do not beleive jurors will live up to their oaths and decide cases based solely on what is placed before them in the trial and not on what else they might have heard about the case.

It is unclear where this newly focused distrust of the jury system got its start, but its biggest boost came last year when the Supreme Court ruled pretrial proceedings could be closed by a judge under limited circumstances when there was a reasonable probability that press reports of pretrial hearings might make it difficult to pick a jury later.

You could almost hear the doors to some courtrooms being gleefully slammed immediately. It was, after all, an easy way out of future jury-selection problems and had the side effect of keeping the public uninformed as to how judges were handling sensitive cases.

In the Washington area, we had been fairly lucky over the past few months. Maybe the judges here had a stronger commitment to public proceedings, or maybe they knew the reporting media here had more money to spend in hiring attorneys to keep courtrooms open.

Whatever their reasons, the judges here had behaved admirably for the most part. The result was a criminal justice system that could be viewd by the public and press and held accountable for its actions.

Times have changes. Two D.C. Superior Court judges recently have closed all or parts of pretrial hearings in criminal cases here at the sole request of defense attorneys. The prosecution vigorously opposed the closings on behalf of the public, but to no avail.

The defendant was no notorious gangster surrounded by hordes of reporters hanging on every word, nor a public official caught with his or her hand in the till. It was just another case among the hundreds brought daily in the Superior Court System -- a serious case involving alleged vicious sexual assaults, to be sure, but, sadly, not the type of incident that would merit much news coverage.

The defense attorneys, though, were able to convice two judges -- Shellie Bowers and David Norman -- that they might have trouble picking a jury in the next couple of months if the hearings were held publicly. Actually, it could have even been a ploy by the defense to attract some publicity to an otherwise routine case. Anyway, the judges went along and closed the hearings on the basis of flimsy argument.

The easy acceptance of the defense argument by two judges here is serious because one courtroom closing seems to beget another. Since it is serious business, judges should authorize court closings -- if at all -- only in the most extremely limited circumstances and not take the easy way out as the Superior Court judges did.

There have traditionally been enough protections built into the jury selection process at time of trial to show that the system can work without the use of dire measures such as closed hearings. There are a lot of acquitted public officials out there who found fair juries despite intense news coverage of their alleged misdeeds.

One of the judges said he was closing the proceeding merely because the defendant asked for it to be closed, and it was up to the defendant to make that decision. That is rather simplistic, since defendants may have many reasons for wanting their conduct or alleged misconduct covered up. (I remember one white-collar criminal who stood tall when he was sentenced to 1-to-3 years in prison, but broke down in tears when he found out the press was there to write about it. Prison, he could take; it was the publicity he could not accept.)

The public has an interest in seeing how its court system works at all phases of the process. Even if those interests have to be balanced at some stages against that of an individual defendant, extreme care should be taken before letting the defendant win that argument.

As for me, I still trust the jury system. It has been around a lot longer than the attorneys and judges who would cast it aside so easily.

Bar News: The D.C. Bar board of governors meetings lately have been filled with two topics of discussion that are still far from resolution: the plan to increase the dues ceiling from $50 to $150, and a plan to revamp the manner in which attorneys are appointed to criminal cases in D.C. Superior Court.

Various members of the bar, still rankled because all of the bar has not been allowed to vote in a referendum on the proposed increase that was passed by the governing board, are still asking for a general vote. The bar board keeps postponing any final action on the proposed referendum, saying it wants to complete its own budget process first.

As for the court-appointment plan that has come up at the last two monthly meetings, the bar board of governors has decided it is too complicated to take up on the regular agenda and has acheduled a special May 6 meeting to discuss the topic in detail.

Allan I. Mendelsohn and Donald E. Ward have formed the firm of Ward and Mendelson. . . U.N. Ambassador Donald F. McHenry will be the speaker at the 1980 Law Day dinner of the Washington Bar Association, scheduled to begin at ( p.m. on April 25 at the Sheraton-Washington Hotel. He will be given the association's "President's Award," while D.C. Superior Court Judge Margaret A. Haywood will receive the Charles H. Houston Medallion of Merit. Haywood will be the first woman recipient of the Houston award. . . Ford Rowan, former NBC News national security correspondent, has joined the Washington office of the North Carolina firm of Sanford, Adams, McCullough and Beard as counsel to the firm. Since resigning from NBC in protest over certain policy decisions in the network's handling of the Iranian hostage crisis, Rowan has taught at the Washington branch of Northwestern University's Medill School of Journalism.