OPINION
¶ 1 Petitioner brings this special action to determine whether the trial court abused its discretion or acted capriciously or arbitrarily in denying his motion for redetermination of the probable cause underlying a manslaughter indictment handed down by a grand jury. A divided panel of the court of appeals affirmed the trial court’s decision. We hold that the denial of Petitioner’s motion was an abuse of discretion and we remand for a redetermination of probable cause.
FACTS AND PROCEDURAL HISTORY
¶ 2 Petitioner Scott Maretick was severely injured and his wife was killed when he lost control of his car and crashed on Frank Lloyd Wright Boulevard in Scottsdale on April 12, 2001. Petitioner’s Corvette was allegedly traveling at approximately 100 miles per hour just before the impact.
¶ 3 Maretick was unconscious at the scene of the accident. His injuries included brain trauma resulting in “permanent cognitive deficit with particular deficit in short-term memory.” As a result of his injuries, Mare-tick was never able to provide investigators with a statement regarding the events leading up to the accident. There are indications that Maretick will never remember the accident or the events immediately following.
¶ 4 On December 18, 2001, the State convened a grand jury to determine whether probable cause existed to charge Maretick with manslaughter. The State presented only one witness, Scottsdale Police Detective Sean Twitchell. Following the prosecutor’s brief examination of the detective regarding the accident, Twitchell was asked a series of questions by the members of the grand jury. The pertinent portion of the grand jury transcript follows:
Grand Juror: What is his [Maretick’s] health, his status now?
Detective Twitchell: Last time I checked, he made pretty much a full recovery.
Grand Juror: Have you spoken with him and asked him why he was traveling like that?
*192 Prosecutor (to Detective Twitchell): You have received no statements; is that correct?
Detective Twitchell: That’s correct.
Grand Juror: Does he have any story to—
Prosecutor (to juror): He [Detective Twitchell] has received no statements.
Grand Juror: I’m sorry.
Prosecutor: Any other questions?
Prosecutor (to Detective Twitchell): There being no further questions, you may be excused.
Following the proceeding, the grand jury returned an indictment for manslaughter against Maretick.
¶5 Maretick filed a motion in superior court requesting a redetermination of probable cause, arguing that he “was denied his right to have the State present evidence to the grand jury in a fair and impartial manner, and was denied substantial due process in having an indictment returned against him with the use of misleading testimony.” His motion contained three arguments: First, he argued that Detective Twitchell knew that his injuries were severe and ongoing,
¶ 6 The trial judge agreed that the detective’s testimony was misleading.
¶ 7 This court has jurisdiction under Article 6, Section 5(1) of the Arizona Constitution and Arizona Rules of Procedure for Special Actions 8(b). See Crimmins v. Superior Court,
DISCUSSION
I. THE GRAND JURY
¶ 8 The Supreme Court has described the grand jury as “a primary security to the innocent against hasty, malicious and oppressive persecution; it serves the invaluable function in our society of standing between the accuser and the accused ... to determine whether a charge is founded upon reason or was dictated by an intimidating power or by malice or ill will.” Wood v. Georgia,
¶ 9 Grand jurors have a light to hear all relevant, non-protected evidence that bears on the case. See id. Thus, if the grand jurors have reasonable ground to believe that other available evidence “will explain away the contemplated charge, they may require the evidence to be produced.” Ariz.Rev.Stat. § 21^12 (2002); see also Crimmins,
II. THE PROSECUTOR’S ROLE
¶ 10 The prosecutor’s role before the grand jury is unique in our system. The prosecutor acts not simply as an advocate, but as a “minister of justice,” who assists the jurors in their inquiry. See Ariz. R. Sup.Ct. 42, ER 3.8 cmt. Prosecutors bear a “particularly weighty duty not to influence the jury because the defendant has no representative to watch out for his interests” before the grand jury. State v. Hocker,
III. DEFENDANT’S CHALLENGE
¶ 11 A grand jury’s finding of probable cause may be challenged only on two grounds: “that an insufficient number of grand jurors concurred in the indictment, or that the defendant was denied a substantial procedural right.” State ex rel. Collins v. Kamin,
¶ 12 In Crimmins, we examined a similar claim of a denial of a substantial procedural right.
¶ 13 The circumstances are similar here. The State presented its case through a single witness, the investigating detective. That witness misled the grand jury by stating that Maretiek had enjoyed a full recovery, when he knew that Maretick’s brain damage was long term, if not permanent. Indeed, he knew that Maretiek was rendered unconscious at the scene and while Maretiek was somewhat improved, he had never regained his memory of the events relating to the accident.
¶ 14 While this misrepresentation alone was not enough to merit a redetermination in this case, the prosecutor assisted in misdirecting the grand jury in two respects. First, he failed to correct the misstatement. Second, he refused to allow the witness to answer the juror’s questions, interposing himself between the juror and the witness in such an intimidating manner that the juror felt compelled to apologize for having asked a question that she had every right to ask— and to have honestly and respectfully answered by the witness. The facts make this case similar to Crimmins, in which this court found a denial of due process leading to an order for remand. But to further sully the picture here, the prosecutor failed to instruct the grand jury that it was Maretick’s right to be free from self-incrimination, that Maretick had no obligation to present evidence, and that the jurors could draw no negative inference from his failure to do so. See State v. Corrales,
1115 The State counters that, while all of the foregoing is true, the errors did not prejudice Maretiek and therefore were harmless. In a criminal proceeding, error “is harmless if we can say, beyond a reasonable doubt, that the error did not contribute to or affect the [outcome]. We must be confident beyond a reasonable doubt that the error had no influence on the jury’s judgment.” State v. Bible,
¶ 16 In determining whether the error was harmless, we consider each misstep in context. See Crimmins,
¶ 17 We do not know why the prosecutor cut off the grand jurors’ questions. The trial judge posited that he did so fearing that the detective’s answer would evoke sympathy from the jurors and prevent an indictment. While sympathy is not a relevant factor in determining probable cause, it is impossible to know where the questioning might have led or how the information might have influenced the jury because of the prosecutor’s untimely interruption. Nor is the fact that Maretick made no statement to the police a relevant factor for consideration in determining probable cause. As a minister of justice, the prosecutor must ensure that the jurors understand such fundamental tenets of law.
¶ 18 In dissenting from the court of appeals decision, Judge Noyes observed that the detective and prosecutor must have feared that the grand jury might not indict:
From this scenario emerges a strong appearance that the prosecutor and the police officer knew that the officer had given false testimony, and that they each acted as they did because they were afraid that the grand jury might not indict Appellant if the officer gave truthful answers to the grand jury’s questions. The real issue here is whether this was a fundamentally fair grand jury process.
Maretick v. Jarrett, 1 CA-SA 02-0116 (Ariz. App. Jul. 22, 2002) (dec. order) (Noyes, J., dissenting). We find that it was not a fundamentally fair process, and we are not convinced, beyond a reasonable doubt, that the errors had “no influence on the jury’s judgment.” Bible,
¶ 19 The grand jury, as an independent body, must be allowed to pursue the investigation as it chooses, unless it is pursuing “clearly improper and unfair lines of inquiry.” State v. Superior Court (Smith),
CONCLUSION
¶ 20 We find that Maretick’s right to due process was violated by the detective’s misleading testimony, coupled with the prosecutor’s interference with the grand jury’s independence and his failure to instruct the jury regarding the pertinent law. We therefore vacate the opinion of the court of appeals, reverse the decision of the superior court, and remand the case for a redetermination of probable cause.
Notes
. Maretick bases this contention upon the affidavit of his daughter, Angela Maretick. In that affidavit, Angela stated that Officer Twitchell contacted her less than a month before the grand jury hearing in an attempt to question Maretick about the accident. Angela avows that she told Detective Twitchell that Maretick’s injuries were long term, that he suffered from permanent brain damage, and that he had no memory of the accident.
. The State has not contended that the detective’s testimony was other than misleading.
. In her minute entry, the judge explained that "it is unclear to the Court why the prosecutor felt it necessary to interrupt the grand juror repeatedly as she attempted to ask questions of the detective, and to answer the questions for him.... It may be that the prosecutor was concerned that an element of sympathy for Defendant might have arisen if the detective was allowed to fully respond to the grand juror’s inquiries, as the Grand Jury would have then been made aware of Defendant’s current medical condition."
. Although instructions to grand juries are usually given before any cases are presented, no rule prohibits giving a later instruction should justice and the needs of the case require that it be given.
. Maretick asks us to dismiss with prejudice, but we do not find here the type of consistent or egregious prosecutorial misconduct necessary for such a determination. See State v. Minnitt,
