Perjury and False Statements

Perjury and lying to investigators are two different crimes, and people confuse them constantly. Perjury means knowingly lying about something material while under oath — in court, in a deposition, or before a grand jury. Lying to a federal agent or investigator, even casually and without ever being sworn in, is its own separate federal crime under 18 U.S.C. § 1001. You do not have to be a witness, a defendant, or under oath for that law to apply. If an agent asks you a question and you knowingly give a false answer about something that matters to their investigation, that alone can be charged — even if you never lied about the thing they were originally investigating. This is why defense lawyers repeat the same advice: you have an absolute right to say nothing, but no right to lie.

Perjury: lying under oath

Perjury is governed mainly by two federal statutes — 18 U.S.C. § 1621 (the general perjury statute) and 18 U.S.C. § 1623 (false declarations before a court or grand jury, which is easier for prosecutors to prove because it doesn't require a second witness to corroborate the lie). Every state also has its own perjury law covering testimony given in state court. To convict someone of perjury, the government generally has to prove:

• The person was under oath (in court, in a deposition, in a sworn affidavit, before a grand jury, etc.);
• They made a false statement;
• They knew the statement was false when they made it (an honest mistake, faulty memory, or guess is not perjury); and
• The false statement was material — meaning it had the potential to influence the proceeding.

Because perjury requires proof of knowing falsity, prosecutions are relatively rare compared to how often people misremember details on the stand. Prosecutors typically reserve perjury charges for cases where the lie is clear-cut and provably deliberate — someone who testifies "I was never at that address" when phone records and their own prior statements put them squarely there, for example.

False statements: lying to investigators (18 U.S.C. § 1001)

This is the statute that trips up far more people than perjury does, precisely because no oath is required. Under 18 U.S.C. § 1001, it is a federal crime to knowingly and willfully make a materially false statement to a federal official or agency in a matter within their jurisdiction — including FBI agents, IRS agents, and other federal investigators. It covers spoken statements during an interview, written statements, and forms. It does not require that you were a suspect, that you were under oath, or that you were formally warned the conversation was an "interview." A friendly-seeming conversation on your porch with an agent who never reads you your rights can still expose you to a false-statements charge if you lie in it.

This statute has produced some of the best-known federal prosecutions in modern memory — people convicted solely because of what they said (falsely) to investigators, not the conduct originally under investigation.

What "materiality" means

Both crimes require the lie to be material — capable of influencing the decision-maker or the investigation, even if it didn't actually change the outcome. Courts interpret this broadly: a false statement doesn't have to be the central fact at issue, only capable of affecting the direction of an investigation or a decision the agency or court had to make. Lying about something that seems small and unrelated — where you were at a certain time, whether you know a certain person — can still be material if it bears on what investigators are trying to figure out.

The "literal truth" defense

One narrow, well-established defense to perjury comes from Bronston v. United States, 409 U.S. 352 (1973), a U.S. Supreme Court case. The Court held that an answer that is literally true — even if evasive, misleading, or non-responsive to the question actually intended — cannot support a perjury conviction under the federal statute. Its reasoning: it's the questioner's job to pin a witness down with a precise question; if the answer given is technically true, the burden of following up falls on the lawyer asking, not the witness.

This is real, but far narrower than people assume, and not a strategy to build on your own. It protects a technically true but misleading answer to an imprecise question — it does not protect an answer a court finds was not actually true, or a false-statement charge under § 1001, which is analyzed differently. Trying to thread a "technically true" needle in real time, without a lawyer, against a trained investigator asking precise follow-ups, is an extremely risky game.

Why you should never lie to investigators

Under the Fifth Amendment, you have the right to remain silent and not incriminate yourself — reinforced for custodial interrogations in Miranda v. Arizona, 384 U.S. 436 (1966). Silence is not a crime; declining to answer, or asking for a lawyer first, carries no criminal exposure by itself. Lying, on the other hand, can become its own charge — often easier for prosecutors to prove than whatever they were originally investigating, since it only requires showing what you said and that it was false.

People lie to investigators for understandable reasons — panic, wanting to protect a friend, embarrassment, or the belief that a small lie is harmless because "it's not really about me." None of that matters to the statute. A false statement made to minimize your own involvement or cover for someone else is charged the same as a lie told to actively obstruct an investigation.

What to do if investigators want to question you

1. You do not have to talk to them. You can politely decline to answer and ask to speak with a lawyer first, whether or not you've been arrested.
2. Do not lie, minimize, or guess to fill a silence. If you don't remember something, say so truthfully rather than guessing and being wrong.
3. Ask whether you are a witness, subject, or target of the investigation. Investigators aren't always required to volunteer this, but asking is reasonable.
4. Get a criminal defense lawyer involved before any interview, statement, or grand jury appearance if you have any reason to think you might be implicated. Under Gideon v. Wainwright, 372 U.S. 335 (1963), you have a right to counsel in a criminal case; a lawyer can also negotiate the terms of an interview or appear with you.
5. If you're served with a grand jury subpoena, note the date immediately. These carry fixed appearance deadlines and sometimes short windows to challenge scope — treat any subpoena as time-sensitive and get it to a lawyer right away.

If you think you already said something false

If you're now worried a past statement wasn't accurate, do not go back and "clean it up" on your own by talking to investigators again without counsel — a follow-up conversation meant to walk something back can create new exposure if handled badly. Correcting the record is sometimes possible and can matter to how a case is charged, but when and how to do it is a judgment call for a lawyer, not something to try alone.

Frequently asked questions

Can I be charged with perjury for something I honestly misremembered?

No. Both crimes require that the false statement was made knowingly — an honest mistake or faulty memory is not perjury. The government must prove you knew the statement was false when you made it.

Do I have to answer questions from an agent who shows up asking about someone else?

No. You can decline and ask for a lawyer, whether the conversation concerns you or someone else. What you can't safely do is agree to talk and then give false information to protect the other person.

Is refusing to answer questions the same as obstructing justice?

No. Declining to speak or asking for a lawyer is not obstruction. Obstruction generally involves affirmative acts like lying, destroying evidence, or tampering with witnesses — not staying quiet.

What's the difference between "taking the Fifth" and lying?

Invoking the Fifth Amendment means declining to answer because a truthful answer might incriminate you — a protected right. Lying is affirmatively giving a false answer instead. The first carries no criminal exposure; the second can be its own crime.

If my lawyer told me what to say, can I still be charged with perjury?

Yes, if the statement itself is knowingly false. A lawyer can help you understand the questions and your options, including declining to answer, but can't make a false statement legally true.

This article is general legal information, not legal advice, and reading it does not create an attorney-client relationship. If you are facing a criminal charge or believe you may be under investigation, talk to a licensed criminal defense lawyer in your state as soon as possible.