An informant in law enforcement is a person who gives police or federal agents inside information about criminal activity, usually from within or close to the criminal networks under investigation. Informants provide access to intelligence that surveillance, wiretaps, and undercover work cannot reach on their own. Federal agencies register and monitor informants under detailed oversight rules, and several Supreme Court decisions set the boundaries on how the government can use them and what it must disclose to defendants.
An informant is not a law enforcement officer. They do not carry a badge, make arrests, or execute warrants. Their job is to pass information to a handler and, when directed, participate in controlled operations under agency supervision.
Types of Informants
The broadest category is the confidential informant, often called a CI. A CI’s identity is protected by the agency they work with, which lets them stay embedded in a drug network, organized crime group, or other criminal organization while reporting back to a handler over weeks, months, or sometimes years. The Supreme Court has long recognized a government privilege to withhold an informant’s identity, grounded in the public interest of keeping information flowing to law enforcement.1Justia. Roviaro v. United States, 353 U.S. 53 (1957)
Cooperating defendants are people already facing criminal charges who agree to provide information in exchange for a lighter sentence or other legal benefits. Under Federal Rule of Criminal Procedure 35, a prosecutor can ask the court to reduce a cooperating defendant’s sentence based on “substantial assistance” in investigating or prosecuting someone else, even after sentencing.2Justia. Federal Rules of Criminal Procedure Rule 35 – Correcting or Reducing a Sentence This arrangement drives many federal drug and organized crime prosecutions.
Citizen informants provide tips out of civic responsibility, with no expectation of payment or legal benefit. Courts generally treat their information as more inherently credible than tips from paid or incentivized sources, precisely because they have no personal stake. Anonymous tipsters who call crime-stopper hotlines or submit tips online without identifying themselves are a related category, though their information usually requires more police corroboration before it can support a warrant or arrest.
Jailhouse informants deserve separate mention. These are inmates who claim a fellow prisoner confessed to a crime. The incentive to fabricate is obvious: an inmate facing serious time has every reason to invent a confession in exchange for a sentencing break. Research has found jailhouse informant testimony present in roughly one in five of the first 367 DNA-based exoneration cases, and the Center for Wrongful Convictions identified false jailhouse informant testimony as the leading cause of wrongful convictions in capital cases. More than 20 states have enacted or proposed legislation addressing the problem, including pretrial reliability hearings and mandatory disclosure of a jailhouse informant’s criminal history, testifying history, and incentives.
How Investigators Use Informants
Informants give investigators access to information that surveillance alone cannot produce. A CI embedded in a drug trafficking organization can identify suppliers, map distribution routes, and pinpoint stash locations. That kind of intelligence might take months of traditional investigation to develop. Some of it would never surface at all.
Beyond gathering intelligence, informants often participate directly in controlled operations. An informant may make a supervised drug purchase, wear a recording device into a meeting, or introduce an undercover officer to a target. These operations run under close police supervision, with agents monitoring in real time and documenting every step for later use as evidence.
The information informants provide frequently forms the backbone of probable cause for search warrants and arrests. The Supreme Court has held that courts evaluating whether an informant’s tip establishes probable cause should consider the “totality of the circumstances,” including the informant’s credibility, basis of knowledge, and any independent police corroboration, to determine whether there is “a fair probability that contraband or evidence of a crime will be found in a particular place.”3Legal Information Institute. Overview of Probable Cause Officers typically verify an informant’s claims through surveillance, records checks, and confirmation of specific details before seeking a warrant.
Compensation and Cooperation Agreements
Informants work for different reasons, and compensation reflects that. Financial payments are common, particularly in federal investigations. The Department of Justice allocates what it calls “confidential funds” specifically for purchasing information from informants, buying evidence, and covering operational expenses like undercover vehicles or business fronts.4Office of Justice Programs. Office of Justice Programs Financial Guide – Part III – Chapter 8 – Confidential Funds
These payments are taxable income. When a federal, state, or local agency pays an informant $600 or more, the agency must report the payment to the IRS on Form 1099-MISC.5Internal Revenue Service. Instructions for Forms 1099-MISC and 1099-NEC Informants who receive cash should expect to owe taxes on it, even when the payment method was designed to protect their identity.
The more powerful incentive in many cases is not money but a reduced sentence. Federal Rule of Criminal Procedure 35 allows the government to ask a court to reduce a cooperating defendant’s sentence, even below a mandatory minimum, if the person provided substantial assistance.2Justia. Federal Rules of Criminal Procedure Rule 35 – Correcting or Reducing a Sentence The government controls this process. Only the prosecution can file the motion, and a defendant who cooperates has no independent right to demand a reduction.
Anonymous tipsters who report through crime-stopper programs may receive modest cash rewards, typically ranging from $1,000 to $50,000 depending on the program and the severity of the crime. The federal Attorney General’s Guidelines prohibit contingent payments, meaning an informant cannot be promised a payment based on the outcome of a case.
Oversight of Federal Informants
Using informants is not an informal arrangement. The Attorney General’s Guidelines Regarding the Use of Confidential Human Sources establish mandatory procedures for federal agencies at every stage of the relationship, from initial recruitment through termination.
Before an informant can be formally registered, the handling agent must document the person’s true identity, criminal history, motivation for cooperating, any promises made to them, and whether they have worked with other government agencies. An FBI supervisor must approve the initial registration based on this suitability assessment, and every registered informant’s file must be reviewed at least once a year.6United States Department of Justice. Attorney General’s Guidelines Regarding the Use of FBI Confidential Human Sources
When an informant is authorized to engage in activity that would otherwise be illegal, like purchasing drugs during a controlled buy, the guidelines require documented justification, specific instructions about what the informant may and may not do, and precautionary measures to limit risk. If the informant acts outside those boundaries, authorization can be suspended or revoked. All payments must be documented, approved at specific dollar thresholds, and subject to formal accounting procedures.
Constitutional Limits on Informant Use
Courts have upheld the government’s use of informants, but with boundaries that matter to anyone whose case involves one.
No Fourth Amendment Protection for Misplaced Trust
The Supreme Court held in Hoffa v. United States that a person has no Fourth Amendment protection against the risk that someone they confide in turns out to be a government informant. Anyone who speaks to another person necessarily assumes the risk that the listener may report the conversation to authorities. That risk, the Court wrote, “is probably inherent in the conditions of human society.”7Library of Congress. Hoffa v. United States, 385 U.S. 293 (1966) Police can generally use informants to gather information from targets without triggering Fourth Amendment scrutiny.
Sixth Amendment Limits After Charges Are Filed
That principle has a hard limit. Under Massiah v. United States, once a person has been formally charged, the government cannot use an informant to deliberately draw out statements about the charged crime without the defendant’s lawyer present. Using statements obtained this way at trial violates the Sixth Amendment right to counsel.8Legal Information Institute. Massiah v. United States, 377 U.S. 201 (1964) The rule does not ban informants in jails after charges are filed. It bars the government from using one to intentionally elicit incriminating statements about the offense that has already been charged.
When a Defendant Can Learn an Informant’s Identity
When a defendant argues they need to know a confidential informant’s identity to prepare a defense, courts apply the balancing test from Roviaro v. United States. The government’s interest in keeping the identity secret is weighed against the defendant’s right to mount a defense. The court considers the crime charged, possible defenses, how significant the informant’s testimony might be, and other case-specific factors. When disclosure would be “relevant and helpful to the defense” or “essential to a fair determination,” the government’s privilege gives way.1Justia. Roviaro v. United States, 353 U.S. 53 (1957)
Mandatory Disclosure of Informant Deals
Prosecutors have an affirmative duty to disclose deals made with informant witnesses. Under Brady v. Maryland, the government must turn over any evidence favorable to the defense that is material to guilt or punishment.9Justia. Brady v. Maryland, 373 U.S. 83 (1963) Giglio v. United States extended that requirement specifically to cooperation agreements: if a witness was promised leniency, immunity, or any other benefit in exchange for testimony, the prosecution must disclose the arrangement. The obligation applies whether the failure to disclose was intentional or merely negligent, and it binds the entire prosecutor’s office. A deal made by one attorney is attributed to the government as a whole.10Justia. Giglio v. United States, 405 U.S. 150 (1972) Jurors cannot evaluate an informant’s credibility without knowing what the informant was promised.
The Risks of Working as an Informant
The role is genuinely dangerous. Informants operate inside criminal organizations where discovery can mean violence or death. A Federal Judicial Center study found that threats of physical harm were the most commonly reported danger to cooperating defendants and witnesses. Documented incidents included homes shot up, houses burned down, and informants’ names posted on public websites built to expose cooperators. At least 31 cooperating defendants have been murdered, both in and out of prison, by people who obtained information about their cooperation from unsealed court documents.
Federal law provides some protection. Under 18 U.S.C. § 1513, retaliating against someone for providing information to law enforcement is a serious federal crime. Killing an informant in retaliation can carry the same punishment as murder. Using physical force or threats in retaliation carries up to 20 years in prison, and non-violent retaliation like interfering with someone’s employment because they cooperated is punishable by up to 10 years.11Office of the Law Revision Counsel. 18 USC 1513 – Retaliating Against a Witness, Victim, or an Informant
A related statute, 18 U.S.C. § 1512, criminalizes using force, threats, or intimidation to prevent someone from communicating with law enforcement in the first place. Attempting to kill someone to stop them from reporting a federal crime carries up to 30 years in prison, and harassment that discourages reporting can bring up to three years.12Office of the Law Revision Counsel. 18 USC 1512 – Tampering With a Witness, Victim, or an Informant Retaliation remains a persistent danger that shapes informant management: it is why identities are protected, why court filings involving cooperators are sometimes sealed, and why some cooperating defendants ultimately enter the federal witness protection program.
Informant Versus Witness
Informants and witnesses play different roles, though the same person can serve as both at different stages of a case. An informant works proactively during an investigation, feeding intelligence about ongoing or planned criminal activity. Their identity is typically confidential, and many informants never appear in a courtroom. A witness, by contrast, provides testimony about events they observed, usually after the fact. Witnesses testify openly, and their identity is disclosed to all parties so the defense can cross-examine them.
The critical moment is when an informant becomes a witness. If the government calls a CI to testify at trial, the informant’s identity comes out, and all the disclosure obligations under Brady and Giglio apply.10Justia. Giglio v. United States, 405 U.S. 150 (1972) Any deals, payments, or promises made must be revealed to the defense. That transition is where the tension between protecting informant identities and ensuring fair trials plays out most visibly in real cases.