The state has the burden. We make them carry it.

Constitutional Defense in California Criminal Cases

Every criminal case in California begins, in some form, with the Bill of Rights. The First Amendment limits what the government can criminalize as speech, threat, or expression. The Fourth Amendment governs whether the police could stop you, search you, or search your property. The Fifth governs whether they could question you and what your silence means. The Sixth governs who represents you, when a jury decides your fate, and what the prosecution must disclose. The Eighth limits bail and punishment. The Fourteenth applies the whole structure to state proceedings and requires due process at every step.

This page is a working guide to those rights as they actually operate in California criminal practice. Each section links to a deeper pillar page on the doctrine, the leading cases, and the practical defenses that flow from it.

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The Bill of Rights at work

The constitutional protections that matter in California criminal defense are not abstract. They translate directly into motions, suppression hearings, jury instructions, plea leverage, and trial outcomes. The most common applications:

First Amendment — speech, expression, and assembly

The First Amendment limits what the government can punish as speech. Most categories of speech are protected, and the unprotected categories — true threats, incitement, fighting words, obscenity, child pornography, defamation — each have a defined constitutional test that the prosecution has to meet. Counterman v. Colorado, 600 U.S. 66 (2023), recently transformed the law of “true threats” by requiring proof that the speaker was at least subjectively reckless about the threatening nature of the communication. That standard now governs California criminal threats prosecutions under Penal Code § 422, cyberstalking under § 646.9, and any other speech-based charge.

In California criminal defense the First Amendment shows up wherever the case is built on words: criminal threats, harassment, cyberstalking, protest arrests, disturbing the peace, restraining orders that try to restrict protected speech, and the right to record police. California Constitution Article I § 2 provides independent and at times broader protection.

Read the full First Amendment defense guide →

Fourth Amendment — search and seizure

The Fourth Amendment requires that searches and seizures be reasonable, and that warrants issue only on probable cause, supported by oath, and particularly describing the place to be searched and the things or persons to be seized. Terry v. Ohio, 392 U.S. 1 (1968), defined the lower “reasonable suspicion” standard that allows brief investigatory stops. Katz v. United States, 389 U.S. 347 (1967), framed the modern “reasonable expectation of privacy” test. Riley v. California, 573 U.S. 373 (2014), held that searching a cell phone incident to arrest requires a warrant.

In California criminal defense, the Fourth Amendment shows up in nearly every case involving physical evidence. If the stop was unlawful, if the search exceeded the warrant, if consent was not freely given, or if the officer relied on a stale or unsupported tip, a properly briefed motion to suppress under Penal Code § 1538.5 can excise the evidence and often end the case.

Read the full Fourth Amendment defense guide →

Fifth Amendment — self-incrimination and due process

The Fifth Amendment protects against compelled self-incrimination, against being tried twice for the same offense, and against deprivation of life, liberty, or property without due process. Miranda v. Arizona, 384 U.S. 436 (1966), requires that police warn a person in custody of the right to silence and the right to counsel before interrogating. Berghuis v. Thompkins, 560 U.S. 370 (2010), then held that the invocation of the right to silence must be unambiguous. Saying nothing is not enough; the suspect has to say so out loud.

In practice this means that the most damaging evidence in a California criminal case is often what the defendant said to police. When statements were taken in custody without a valid waiver, or after the suspect invoked counsel, those statements can be excluded.

Read the full Fifth Amendment defense guide →

Sixth Amendment — counsel, speedy trial, confrontation, jury

The Sixth Amendment guarantees the right to counsel, to a speedy and public trial, to an impartial jury, to be informed of the charges, to confront witnesses, and to compel witnesses in the accused’s favor. Gideon v. Wainwright, 372 U.S. 335 (1963), made the right to counsel binding on the states. Strickland v. Washington, 466 U.S. 668 (1984), set the standard for evaluating whether counsel was constitutionally effective.

For California defendants this is the constitutional source of: the right to a lawyer at every critical stage, the right to a jury of twelve on felonies, the right to cross-examine the prosecution’s witnesses in person, and the right to subpoena defense witnesses. It is also the source of Brady and discovery obligations that affect how cases are litigated long before trial.

Read the full Sixth Amendment defense guide →

Eighth Amendment — bail, fines, and punishment

The Eighth Amendment forbids excessive bail, excessive fines, and cruel and unusual punishment. In California, this is the constitutional source for bail review, for proportionality challenges to fines and fees, and for limits on sentencing in extreme cases. In re Humphrey, 11 Cal. 5th 135 (2021), reshaped California bail by holding that a court cannot set bail in an amount that effectively detains an accused without considering ability to pay and non-monetary alternatives.

Read the full Eighth Amendment defense guide →

Fourteenth Amendment — due process and equal protection

The Fourteenth Amendment is the structural bridge that applies the Bill of Rights to the states. Its Due Process Clause requires fair procedure before any deprivation of liberty, and its Equal Protection Clause forbids selective enforcement on impermissible grounds. Brady v. Maryland, 373 U.S. 83 (1963), grounded in due process, requires prosecutors to disclose material exculpatory evidence to the defense.

In California criminal defense the Fourteenth Amendment shows up wherever procedure is in question: probation revocation hearings, restraining order proceedings, plea colloquies, sentencing, and any allegation that the prosecution withheld evidence that could have changed the result.

Read the full Fourteenth Amendment defense guide →

California Constitution Article I — broader protection where it matters

California’s own Constitution often grants broader protection than the federal floor. Article I § 13 governs search and seizure, and California courts have at times read it more protectively than the federal Fourth Amendment. Article I § 15 sets out the rights of the accused. Article I § 7 contains California’s due process and equal protection guarantees. Article I § 28 (the Victims’ Bill of Rights) introduced significant changes to bail, sentencing, and victim participation that defense counsel must work around.

A complete California criminal defense never relies solely on the federal Constitution. It pleads and argues parallel state grounds because the California Supreme Court has the final word on the meaning of California’s own Constitution.

Read the full California Constitution defense guide →

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How the rights work together in a typical case

Constitutional defenses are not silos. A traffic stop that produced drug evidence will usually implicate the Fourth Amendment (was the stop lawful, was the search lawful) and the Fifth Amendment (were any statements taken voluntarily and after a valid Miranda waiver) and the Sixth Amendment (was counsel offered and respected). A motion to suppress under Penal Code § 1538.5 is often joined with a motion to exclude statements and a motion in limine to limit cross-examination.

Reading the case constitutionally, end to end, is what separates a posture of defense from a posture of damage control.

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Frequently asked questions

What constitutional rights do I have if I am arrested in California?

At minimum, you have the right to free speech and expression under the First Amendment, the right to remain silent under the Fifth, the right to counsel under the Sixth, the right to be free from unreasonable search and seizure under the Fourth, the right to a reasonable bail determination under the Eighth, and the right to due process and equal protection under the Fourteenth. The California Constitution provides parallel and sometimes broader protection. The single most consequential right at the moment of arrest is the right to remain silent. Saying nothing until counsel is present rarely hurts a case and often saves it.

Can I be prosecuted for things I said?

Only within strict First Amendment limits. Speech is presumptively protected. The narrow categories of unprotected speech — true threats, incitement, fighting words, obscenity, child pornography, defamation — each carry a defined constitutional test that the prosecution has to meet. After Counterman v. Colorado, 600 U.S. 66 (2023), prosecutions premised on a threat theory require proof that the speaker was at least subjectively reckless about whether the words would be understood as threatening.

Does California give me more protection than the federal Constitution?

Sometimes, yes. California courts construe Article I of the state Constitution, and on issues from search and seizure to free speech to the right to privacy they have at times read it more broadly than the federal floor. A well-pleaded motion in a California criminal case argues both grounds.

Can police search me without a warrant?

Yes, in defined circumstances. Recognized warrant exceptions include consent, search incident to a lawful arrest, automobile searches supported by probable cause, exigent circumstances, plain view, and inventory searches. The defense work is in testing whether each exception actually applied on the facts.

When does the right to counsel attach?

The Sixth Amendment right to counsel attaches at the initiation of adversarial judicial proceedings, typically the filing of charges or the first appearance. The Fifth Amendment right to counsel during custodial interrogation under Miranda attaches earlier, the moment a person in custody is interrogated. Both matter, and they protect different things.

What is the exclusionary rule?

The exclusionary rule keeps evidence obtained through a Fourth Amendment violation out of the prosecution’s case-in-chief. It exists to deter unconstitutional searches by removing the incentive to conduct them. The rule has exceptions, including good faith and inevitable discovery, which is why suppression motions turn on detailed factual records.

How do constitutional defenses actually affect the outcome of a case?

Two ways. First, by excluding evidence the prosecution needs, which can end a case before trial. Second, by reshaping leverage. A prosecutor who is about to lose key evidence on a motion will often negotiate a different result. Most constitutional victories never see a verdict, because the case resolves before one is needed.

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Cases and statutes referenced on this page

• Counterman v. Colorado, 600 U.S. 66 (2023) — First Amendment requires subjective recklessness for true threats.
• Brandenburg v. Ohio, 395 U.S. 444 (1969) — incitement requires imminent lawless action.
• Terry v. Ohio, 392 U.S. 1 (1968) — reasonable suspicion standard.
• Katz v. United States, 389 U.S. 347 (1967) — reasonable expectation of privacy.
• Riley v. California, 573 U.S. 373 (2014) — warrant required to search a cell phone incident to arrest.
• Miranda v. Arizona, 384 U.S. 436 (1966) — custodial interrogation warnings.
• Berghuis v. Thompkins, 560 U.S. 370 (2010) — invocation of silence must be unambiguous.
• Gideon v. Wainwright, 372 U.S. 335 (1963) — right to counsel in state criminal cases.
• Strickland v. Washington, 466 U.S. 668 (1984) — standard for effective assistance of counsel.
• Brady v. Maryland, 373 U.S. 83 (1963) — prosecutorial duty to disclose exculpatory evidence.
• In re Humphrey, 11 Cal. 5th 135 (2021) — California bail must consider ability to pay.
• U.S. Const. amends. I, IV, V, VI, VIII, XIV.
• Cal. Const. art. I §§ 2, 3, 7, 13, 15, 28.
• Cal. Penal Code § 422 — criminal threats.
• Cal. Penal Code § 1538.5 — suppression motion procedure.

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Related practice areas

• Criminal Defense — practice overview
• DUI Defense (Los Angeles County)
• Drug Crime Defense
• Domestic Violence Defense (PC 273.5)
• What to do when you are pulled over in California
• What to do if you are arrested in California

The Constitution is the first defense.

Attorney Advertising. Zak Fisher, Esq. — California Bar #332712. This page is for general information about California criminal defense law and is not legal advice for any particular case. Reading this page does not create an attorney-client relationship. Past results do not guarantee future outcomes.