If a prosecutor knew of evidence that tends to explain away a felony charge but did not tell the grand jury about it, Penal Code section 939.71 may provide a basis to challenge the related part of the indictment. An omission alone does not automatically dismiss a charge: the defendant must show substantial prejudice. The grand jury also is not required to hear every item of defense evidence, though it must weigh evidence presented and order available evidence it has reason to believe will explain away the charge. (Penal Code § 939.71; § 939.7)
Confirm what the prosecutor knew and what the grand jury heard
Start with the exact evidence said to be exculpatory: what fact it tends to negate, when the prosecutor learned of it, and what the evidence actually shows in context. Then compare that information with the grand-jury record. Penal Code section 938.1 provides for a certified transcript after indictment; counsel can compare the testimony and exhibits with the known evidence and any description given to the grand jury. The important questions include whether the prosecutor knew of the item, whether it tended to explain away a charge, and whether the grand jury was told its nature and existence. (Penal Code § 939.71; § 938.1)
Section 939.7 does not turn the grand jury into a trial or require presentation of every defense theory. It says the jury must weigh evidence it receives and order evidence that is available and that it has reason to believe will explain away the charge. Section 939.71 separately requires a prosecutor who is aware of exculpatory evidence to inform the grand jury of the evidence’s nature and existence and of its section 939.7 duties. (Penal Code § 939.7; § 939.71)
The remedy depends on substantial prejudice
A court may dismiss only the portion of the indictment related to the omitted evidence, and only if the failure caused substantial prejudice. As Berardi explains, the question is whether it is reasonably probable that a properly informed grand jury would not have found probable cause on the related charge. The court compares the omitted evidence with what the grand jury heard; evidence of guilt remaining in the record does not, by itself, end that inquiry. Johnson v. Superior Court discusses the prosecutor’s duty; Berardi v. Superior Court applies the substantial-prejudice requirement. Neither supports automatic dismissal whenever evidence was omitted. (Penal Code § 939.71; Johnson v. Superior Court; Berardi v. Superior Court)
Preserve the relevant evidence, records showing when the prosecutor learned about it, the indictment, and the certified transcript and exhibits. Counsel can assess what motion is available and whether the omission affected a specific count or allegation. Do not assume the target personally has a right to present witnesses before indictment or to obtain the grand-jury materials before the statutory process permits it.
The Law Offices of David S. Chesley represents people facing California felony charges. Call (800) 755-5174 to discuss the indictment record and a possible challenge.