Yes, but California does not allow a conviction based only on the uncorroborated testimony of a qualifying in-custody informant. Other evidence must connect the defendant to the charged offense. Evidence showing only that a crime happened is insufficient for that purpose. The same rule applies when the testimony is used to find a special circumstance true or a fact in aggravation. These limits come from Penal Code section 1111.5.
An informant’s account can still affect a serious felony trial when the legal requirements are met and the fact-finder finds it credible. Corroboration and credibility are different questions: a piece of evidence may provide the required independent link while leaving significant doubt about the informant’s story.
Who counts as an “in-custody informant” under this rule?
For section 1111.5, the witness must describe statements the defendant allegedly made while both were held in a city or county jail, state penal institution, or correctional institution. The statute excludes a codefendant, eyewitness to the event (a “percipient witness”), accomplice, or coconspirator from this particular definition. An excluded witness may raise other evidence issues, but calling every jailed witness an in-custody informant would misstate this rule. The witness’s status and the source of the claimed information must be established before applying the statute. Penal Code § 1111.5(b).
For example, a cellmate who says the accused confessed to a homicide during detention may fit the definition. A person who says they saw the homicide happen before being jailed is a different kind of witness. A codefendant who recounts a conversation may be evaluated under other rules, including accomplice rules where applicable. The label alone does not decide whether testimony is admissible, corroborated, or believable.
What must corroborating evidence do?
The other evidence must tend to connect the defendant with the offense or with the particular special circumstance or aggravating fact at issue. Proof that a victim died, for example, establishes an event; standing alone, it does not corroborate an informant’s claim that this defendant committed it. A separate item—such as reliable evidence placing the defendant in a relevant act—might provide a connection, depending on what it actually proves. The court assesses the evidence in the specific case. Penal Code § 1111.5(a).
One in-custody informant generally cannot corroborate another. There is an exception if the party calling the witness proves, by a preponderance of the evidence, that the informants did not communicate on the subject of their testimony. The statute does not say they must have been physically separated. Even when that exception is established, the jury still has to assess whether the accounts are trustworthy. Penal Code § 1111.5(a).
Why do benefits and access to case facts matter?
An informant may expect a plea deal, sentence change, money, improved custody conditions, or another benefit. When the prosecution calls an in-custody informant, Penal Code section 1127a requires a written court filing stating consideration promised or received, with that statement provided to the defense before trial. The statute defines “consideration” broadly; the filing requirement does not narrow other discovery rights.
The defense can compare the claimed confession with what the informant could have learned from news reports, other people in custody, shared paperwork, or prior interviews. It can examine when the account first appeared, how its details changed, whether anyone recorded it, and whether the informant disclosed the alleged statement before discussing a possible benefit. These are credibility checks. They do not automatically show that the witness lied.
On a party’s request, section 1127a also requires a jury instruction telling jurors to examine in-custody informant testimony with caution and close scrutiny, including any benefit the witness received or expected. The instruction does not tell jurors to reject the testimony automatically. A defendant should discuss the witness’s statutory status, corroboration, benefits, and proposed jury instructions with counsel well before trial.
A focused review of an informant claim
A useful case review separates four questions:
- Source: What words does the witness claim the defendant said, where and when, and who else could have heard them?
- Independent link: What evidence outside this informant’s account connects the defendant to the specific charge or allegation?
- Information path: Could the witness have learned the details elsewhere, including through another in-custody informant?
- Incentive: What was promised, received, requested, or expected, and when did that arise?
The answers may support a challenge to the testimony, narrow its weight, or show that independent evidence exists. No single defect guarantees dismissal or acquittal. The Law Offices of David S. Chesley can review a claimed jailhouse confession alongside the other evidence in a case. See the firm’s Los Angeles homicide defense page or call (800) 755-5174 to discuss the specific accusation.