Is it legal to lie to a US federal law enforcement officer?
<p>If a law enforcement officer stops someone on the street and asks questions related to an investigation, the person is not under oath.  The person therefore presumably cannot be prosecuted for perjury.</p>

<p>Assuming the person decides to respond to the questions, is there any federal law requiring the responses to be truthful?  If so:</p>

<ul>
<li>What law or laws apply?</li>
<li>Does the law supply a definition of "truth"?  Must it be "the whole truth and nothing but the truth," or is there a different standard?</li>
</ul>

<p>One reason for this question is interest in the degree of inequality between an interrogating officer and the subject of the interrogation, in light of the fact that the officer is allowed to lie.</p>

<p>This is one of the things Martha Stewart was convicted of. <a href="https://www.law.cornell.edu/uscode/text/18/1001" rel="nofollow">18 USC 1001</a> is the US federal law requiring truthfulness. That statute forbids you to falsify, conceal, or cover up a material fact. One limitation on how broad this law is, is that it has to be a matter "within the jurisdiction of the executive, legislative, or judicial branch of the Government of the United States". If your neighbor is an FBI agent and he asks if you're the one who broke his window, and you lie, that's not a federal matter.  Another limitation is that the lying has to be material.</p>

<p>The essential part of the law is subsection (a). Subsection (b) then 
states an exception:</p>

<blockquote>
  <p>(b) Subsection (a) does not apply to a party to a judicial proceeding,
  or that party’s counsel, for statements, representations, writings or
  documents submitted by such party or counsel to a judge or magistrate
  in that proceeding.</p>
</blockquote>

<p>Then you also owe a lesser duty of truthfulness to the legislature.</p>

<p>Taking note of <a href="https://supreme.justia.com/cases/federal/us/468/63/" rel="nofollow">US. v. Yermian</a>, it is not required that the person you lie to be a federal officer. Yermian lied to his employer, who was a defense contractor, and the fact that the relevant form was submitted to the government for scrutiny is what made it a matter in federal jurisdiction. Comparing the wording of 1001 to the <a href="https://www.law.cornell.edu/uscode/text/18/1621" rel="nofollow">perjury statute</a>, the operative expression for perjury involves statements "which he does not believe to be true", we can see that the perjury statute requires telling the literal truth (see <a href="https://scholar.google.com/scholar_case?case=13780249773976859407&amp;hl=en&amp;as_sdt=6&amp;as_vis=1&amp;oi=scholarr" rel="nofollow">Bronston v. US</a>), which allows so-called lies of omission (of a particular subtype: much more could be said about that). In contrast the lying statute forbids both literally false statements and concealing of the truth.</p>

<p>I don't have cases at my fingertips that indicate how broad your truthful answers have to be, for example if you think the FBI is trying to put away a friend and ask you about what he did on June 14, and you know that he did a bad thing on June 13, would it be lying in the relevant sense to conceal that fact which they didn't ask about.</p>

<p>[ADDENDUM]</p>

<p>A session of perusing cases has led to a tiny bit of further information. A literal reading of the statute says that you are in violation of the law if you falsify a fact (sloppy epistemology, unless it refers just to altering records and evidence), or conceal a fact, and the courts recognise this as a fundamental division. As for falsifying, the way that has been applied is to refer to cases where the accused makes a statement which asserts something that he knows to be untrue. Thus, saying "No" to a question when the truth is "Yes" is a violation.</p>

<p>A propos concealment, in <a href="https://law.resource.org/pub/us/case/reporter/F2/320/320.F2d.898.282.27853_1.html" rel="nofollow">US v. Diogo 320 F.2d 898</a> the court states that</p>

<blockquote>
  <p>False representations, like common law perjury, require proof of
  actual falsity; concealment requires proof of wilful nondisclosure by
  means of a 'trick, scheme or device.'</p>
</blockquote>

<p>This case is pre-Bronston so there is mixing of concepts from perjury law and lying law, which would not happen now, but we can steering clear of their perjury citations. The crucial fact is that accused(s) were technically married in New York, for immigration purposes, and they were accused of a 1001 violation for having indicated that they were married. Part of the government's case was that such a marriage is not valid, and the court rejected that conclusion. The government's second prong was to maintain that the court "should affirm appellant's convictions on a theory of concealment", and this too the court rejected, saying "proof of their ulterior motives in marriage would not be tantamount to proof of willful and knowing concealment of these material facts". What they said on the forms was literally true, and they did not have a duty to volunteer information that they probably knew the government was interested in.</p>

<p>Contrarily in a later case, <a href="http://openjurist.org/870/f2d/1047/united-states-v-zalman" rel="nofollow">US v. Zalman 870 F.2d 1047</a> we are told that</p>

<blockquote>
  <p>the underlying purpose of a marriage is a material fact which bears
  upon the validity of the marriage, and that any false or fraudulent
  misrepresentation regarding the actual purpose of a marriage in order
  to gain status as a resident of the United States can be punished
  under 18 U.S.C.A. § 1001</p>
</blockquote>

<p>so you have to be more truthful than the literal truth standard.</p>

<p>There are also circumstances where there is an independent duty to give information, such as reporting income to the IRS. In <a href="http://openjurist.org/798/f2d/1570/united-states-v-hernando-ospina" rel="nofollow"><em>US v. Hernando Ospina</em> 798 F.2d 1570</a> the court maintained </p>

<blockquote>
  <p>It is clear that in order to support a section 1001 concealment
  conviction there must be a legal duty to disclose the facts the
  defendant was convicted of concealing</p>
</blockquote>

<p>citing <a href="http://openjurist.org/706/f2d/1092/united-states-v-j-tobon-builes" rel="nofollow">US v. Tobon-Builes 706 F.2d 1092</a>, where again there was a legal duty to report "existence, origin, and transfer of approximately $185,200 in cash".</p>

<p>In other words, it is not clear what information you are allowed to <em>not</em> volunteer when asked a question in a federal matter.</p>

<p>Yes. <a href="https://www.law.cornell.edu/uscode/text/18/1001" rel="nofollow noreferrer">18 USC 1001</a>:</p>
<blockquote>
<p>(a) Except as otherwise provided in this section, whoever, in any matter within the jurisdiction of the executive, legislative, or judicial branch of the Government of the United States, knowingly and willfully—</p>
<p>(1) falsifies, conceals, or covers up by any trick, scheme, or device a material fact;</p>
<p>(2) <strong>makes any materially false, fictitious, or fraudulent statement or representation;</strong> or</p>
<p>(3) makes or uses any false writing or document knowing the same to contain any materially false, fictitious, or fraudulent statement or entry;</p>
<p><strong>shall be fined under this title, imprisoned not more than 5 years</strong> or, if the offense involves international or domestic terrorism (as defined in section 2331), imprisoned not more than 8 years, or both. If the matter relates to an offense under chapter 109A, 109B, 110, or 117, or section 1591, then the term of imprisonment imposed under this section shall be not more than 8 years.</p>
</blockquote>
<p>The base offence level under the sentencing guidelines is 14, same as for perjury.</p>
<p>Incidentally, I have no idea where you got the idea it's legal to lie to a state cop. That can very well be obstruction of justice, also a crime. Don't lie to cops.</p>

<p>In America, it is a federal crime to lie to an FBI agent, however it is not criminal for an FBI agent to lie to you.  In fact, it is common practice for them to do so in their pursuit of evidence.</p>

<p>In short, American citizens (the most incarcerated people in the world per capita) are held to a higher standard than the lands highest law enforcement.</p>

<blockquote>
  <p>Title 18, United States Code, Section 1001 makes it a crime to: 1)
  knowingly and willfully; 2) make any materially false, fictitious or
  fraudulent statement or representation; 3) in any matter within the
  jurisdiction of the executive, legislative or judicial branch of the
  United States. Your lie does not even have to be made directly to an
  employee of the national government as long as it is "within the
  jurisdiction" of the ever expanding federal bureaucracy. Though the
  falsehood must be "material" this requirement is met if the statement
  has the "natural tendency to influence or [is] capable of influencing,
  the decision of the decisionmaking body to which it is addressed."
  United States v. Gaudin , 515 U.S. 506, 510 (1995). (In other words,
  it is not necessary to show that your particular lie ever really
  influenced anyone.)</p>
</blockquote>

<p><a href="http://www.wisenberglaw.com/Articles/How-to-Avoid-Going-to-Jail-under-18-U-S-C-Section-1001-for-Lying-to-Government-Agents.shtml" rel="nofollow">- Solomon L. Wisenberg</a></p>

united-states police