THE SIXTH Amendment says that "{I}n all criminal prosecutions, the accused shall enjoy the right ... to be confronted with the witnesses against him." But the Supreme Court has now decided that in certain circumstances, the primary witness in a criminal trial need not come into court and face the accused while giving testimony: a victim in a child abuse case who will suffer serious emotional distress may testify in a separate room while a closed-circuit TV camera records the testimony and broadcasts it to the courtroom.

Child abuse, a particularly horrible offense against particularly helpless victims, occurs widely and is often hard to prove in court. Many victims are too young even to be called as witnesses, and others are often frightened, confused to have suffered at the hands of someone who was supposedly a protector and intimidated by the crowded courtroom, the questioning lawyers, the black-robed judge and most of all by the accused.

To shield the sexually abused child from trauma while attempting to protect the Sixth Amendment rights of the accused, 37 states permit the use of videotaped testimony; 24 authorize one-way closed-circuit television and eight allow two-way television transmission of testimony. The Maryland statute at issue here authorizes a one-way system, requires a judge to determine that the child victim will suffer serious emotional distress if forced to testify in the presence of the accused and allows both prosecuting and defense attorneys to be with the child during questioning. It also provides for electronic communication between the accused and his lawyer throughout the proceedings.

The confrontation clause is in the Bill of Rights for a reason that the court, in an earlier case, summarized in these words: "It is always more difficult to tell a lie about a person to his face than behind his back. ... That face-to-face presence may, unfortunately, upset the truthful rape victim or abused child, but by the same token it may confound and undo the false accuser or reveal the child coached by a malevolent adult."

But if truth-telling is the standard, then it must be acknowledged that there are also circumstances in which it is more difficult to tell the truth about a person to his face. Direct confrontation may indeed ''undo'' the false accuser. But it is not simply that confrontation may ''upset'' the truthful abused child: it may devastate the child and warp his testimony, and that prospect may so alarm the parent that the child is kept off the stand. These are the insistent considerations that hedge the mandate of the Sixth Amendment.