The defendant appeals his conviction in the Superior Court {Smith, J.) for conduct after a motor vehicle accident, RSA 264:25, and false reporting of an accident, RSA 264:28 (Supp. 1988). He argues that the trial court erred in denying his motion to dismiss or, in the alternative, to quash the indictments against him because two unauthorized police officers were present in the grand jury room during one witness’ testimony. We hold that the presence of the unauthorized individuals violated Supreme Court Rule 52, and we therefore reverse and order the indictments quashed.
The charges against the defendant resulted from a March 7, 1987 incident in which a pedestrian was struck by a motor vehicle which subsequently fled the scene. During the testimony of one witness before the Grafton County Grand Jury, the county attorney arranged to have present in the grand jury room two police officers who had already testified, so that they could take notes on the witness’ testimony. This witness had previously given the prosecu*537tor a statement exculpating the defendant. Before the grand jury she offered testimony linking the defendant to the March 7 incident. The grand jury returned a two-count indictment against the defendant charging him with conduct after an accident, RSA 264:25, and false reporting of an accident, RSA 264:28 (Supp. 1988).
The defendant filed a motion to dismiss or, in the alternative, to quash the indictments. After a hearing, the court denied the motion, ruling that although the presence of the officers was an “irregularity,” “in the absence of evidence of prejudice, the irregularity affords no ground for quashing the defendant’s indictment.” The court also ruled that the statute providing that a grand jury may appoint one of its members to act as clerk, RSA 600:5, was not relevant in determining whether police officers were prohibited from taking notes in the grand jury room.
The defendant was found guilty on both counts after a jury trial. On appeal, he contends that the police officers’ presence in the grand jury room was impermissible and that the indictments against him should therefore be dismissed. We hold that although a non-prejudicial irregularity in grand jury procedure is generally insufficient to warrant dismissal, no indictment may stand where an unauthorized person has invaded the secrecy of a grand jury proceeding in violation of Supreme Court Rule 52.
In New Hampshire, grand jury proceedings are little regulated by the State Constitution or by statute. See N.H. Const. pt. I, art. 15; RSA ch. 600; see also State v. Canatella, 96 N.H. 202, 204, 72 A.2d 507, 508 (1950). Nonetheless, “this court has long recognized the traditional secrecy of grand jury proceedings.” State v. Damiano, 124 N.H. 742, 748, 474 A.2d 1045, 1049 (1984). To protect that secrecy, as well as to promote “orderly and uninfluenced proceedings,” the common law required “excluding unauthorized persons from both the investigations and the deliberations of the [grand] jury.” Canatella, supra at 205, 72 A.2d at 509. Until 1985, however, irregularities in grand jury proceedings did not require quashing the challenged indictments in the absence of prejudice to the defendant. See Canatella supra.
That year, this court adopted Supreme Court Rule 52, which carved out an exception to that general rule. Rule 52 established the only means by which an individual other than the prosecutor, the jurors, or a witness, may be authorized to “be present while the grand jury is taking evidence.” Sup. Ct. R. 52(4); cf. Canatella supra (predating Rule 52). The county attorney or attorney general must seek authorization for any additional presence in the grand jury room from a justice of the superior court.
*538The State concedes that it failed to obtain the court’s authorization for the police officers’ presence in the grand jury room, and we therefore order the indictments quashed. Because of the result reached, we need not address other issues raised by the parties.
Reversed and remanded.
Souter, J., with whom Thayer, J., joined, dissented; the others concurred.