A 402 hearing in California is a proceeding under Evidence Code Section 402 where the judge decides whether a piece of evidence is admissible before the jury is allowed to hear it. The hearing happens outside the jury’s presence, and the ruling can reshape what the trial looks like from that point forward. If you are a party, a witness, or someone following a case, this is the mechanism that explains why certain evidence reaches the jury and other evidence never does.
What Section 402 Does
The statute is short and does three things. When a “preliminary fact” is in dispute, the court has to resolve that dispute before the evidence tied to it can come in. A preliminary fact is any fact that determines whether evidence is admissible, including whether a witness is qualified to testify or whether a privilege applies.1California Legislative Information. California Code EVID – Section 400
The court has discretion to hold these hearings outside the jury’s presence for any kind of evidence. In criminal cases, the judge must hold the hearing outside the jury’s presence when the question is whether a defendant’s confession or admission is admissible, so long as either side asks. The difference between “may” and “shall” is doing real work in that sentence.2Justia. California Code EVID – Sections 400-406
When the judge rules on admissibility, that ruling automatically includes whatever factual finding was needed to reach it. No separate written finding is required unless another statute specifically calls for one.2Justia. California Code EVID – Sections 400-406
When a 402 Hearing Happens
A 402 hearing can take place before trial or during it. Evidentiary challenges commonly surface at pretrial conferences, when both sides are narrowing the issues and setting a schedule. Judges also pause mid-trial when a dispute pops up unexpectedly, sending the jury out while the lawyers argue over whether something should come in.
Either side can request the hearing. Attorneys often frame the request as a motion in limine, which is a request to resolve an evidentiary issue before the jury is exposed to it. California courts treat Section 402 as the statutory authority behind motions in limine; the motion is the vehicle and Section 402 is the engine.
There is no rigid format. The request can be raised orally in court or in a written motion, depending on the judge’s preferences and local rules. What matters is that the challenge is raised before the disputed evidence reaches the jury.
The Confession Rule in Criminal Cases
The one scenario where the judge has no discretion involves confessions. If either side asks for a hearing on whether a defendant’s confession or admission is admissible, the hearing has to be held outside the jury’s presence.2Justia. California Code EVID – Sections 400-406 The concern behind that rule is straightforward. Once a jury hears a confession, an instruction to disregard it cannot really undo the effect if the confession turns out to have been obtained improperly.
What Kinds of Evidence Get Challenged
A 402 hearing can address almost any evidentiary dispute. A few categories come up over and over.
Hearsay
Hearsay is an out-of-court statement offered to prove the truth of what it asserts, and California treats it as inadmissible unless an exception applies.3California Legislative Information. California Code EVID – Section 1200 The problem is that the person who originally spoke is not in court to be cross-examined. A 402 hearing lets the judge decide whether an exception genuinely fits, such as a spontaneous statement, a business record, or a statement by a party opponent. If the proponent cannot make that showing, the statement stays out.
Expert Testimony
Expert witnesses face two separate screens in California. When an expert relies on a novel scientific technique, California uses the Kelly-Frye standard: the technique must have gained general acceptance in the relevant scientific community before an expert can testify about its results.4Stanford Supreme Court of California. People v Kelly The rule originated in a case about voiceprint identification and has since been applied to areas like DNA testing and some sobriety tests.
Beyond novel science, all expert testimony has to survive the gatekeeping role laid out in Sargon Enterprises v. University of Southern California. Under that decision, the trial judge has a duty to exclude expert opinions that are speculative, based on unreliable material, or built on reasoning that amounts to a logical leap rather than sound analysis.5Justia. Sargon Enterprises Inc v University of Southern California The judge is not supposed to weigh who is more persuasive. The question is narrower: does the reasoning hold together, and does the underlying data support the opinion?
A 402 hearing is the primary mechanism for testing an expert before any jury exposure. It’s where lawyers probe methodology, the data behind the opinion, and whether the expert is qualified in the specific area at issue.
Character Evidence and Section 352
Character evidence and prior-conduct evidence are among the most fought-over categories at trial. Even when this kind of evidence is technically relevant, judges often exclude it under Evidence Code Section 352, which allows exclusion when the probative value is substantially outweighed by the risk of undue prejudice, confusion, or wasted time.6California Legislative Information. California Code EVID – Section 352
Section 352 balancing shows up constantly in 402 hearings. A prosecutor may want to introduce a defendant’s prior convictions. The defense may argue the jury will convict based on dislike rather than the current evidence. The 402 hearing gives the judge room to weigh that tradeoff away from the jury, and the ruling can narrow or widen what the jury eventually learns about a party’s background.
Who Has to Prove What
The party trying to get evidence admitted carries the burden. Under Section 403, the proponent has to produce enough evidence to support a finding that the preliminary fact exists. If the preliminary fact concerns the relevance of the evidence, a witness’s personal knowledge, the authenticity of a document, or whether a specific person made a particular statement, the evidence stays out unless the proponent clears that threshold.7California Legislative Information. California Code EVID – Section 403
For preliminary facts not covered by Section 403, Section 405 tells the judge to identify which side has the burden based on the underlying rule of law, then decide the fact and admit or exclude the evidence. If a preliminary fact also happens to be a fact the jury will need to decide in the case, the jury is never told what the judge concluded. The two determinations stay separate.2Justia. California Code EVID – Sections 400-406
What Happens if the Ruling Is Violated
Once the judge rules that evidence is excluded, mentioning it in front of the jury is not just a slip. Trial courts have inherent authority to sanction attorneys who violate an exclusion order, and consequences can include monetary penalties, contempt findings, or a mistrial. A mistrial is considered an extreme remedy, used only when nothing else can fix the problem.
Timing matters if the other side violates a ruling. An attorney who wants a mistrial generally needs to ask for it immediately after the violation, not later. Waiting can be treated as waiving the issue, and the judge may decide that a curative instruction to the jury was enough. In practice, most violations result in a warning to the offending attorney and an instruction telling the jury to disregard what they heard.
Preserving the Issue for Appeal
Losing a 402 hearing is not necessarily the end of the road, but preserving the issue requires care during the hearing itself. California law requires two things for a reversal based on an evidentiary error: a timely objection (or motion to exclude or strike) that clearly states the specific ground, and a conclusion by the appellate court that excluding the evidence would have been correct and that the error caused a miscarriage of justice.8California Legislative Information. California Code EVID – Section 353
The second requirement is the hard one. California appellate courts review most evidentiary rulings under the abuse of discretion standard, meaning the trial judge’s decision stands unless it was arbitrary, irrational, or based on an incorrect understanding of the law. When the issue turns on a pure legal question, such as what a section of the Evidence Code means, the appellate court reviews it fresh without deferring to the trial judge.
The practical takeaway is that vague objections sink appeals. Saying “I object” without stating a specific evidentiary ground is not enough. If evidence was excluded, the losing side needs to make an offer of proof on the record, explaining exactly what the jury would have heard. Without that record, there is nothing for the appellate court to review.