Motions to Suppress and Traverse in California

Challenging Unconstitutional Searches and Seizures Under Penal Code §1538.5

The Fourth Amendment to the United States Constitution and Article I, Section 13 of the California Constitution protect individuals from unreasonable searches and seizures. These protections apply not only to homes and vehicles but also to electronic data, cellphones, and personal effects.

When law enforcement oversteps these constitutional boundaries, defense attorneys can file a motion to suppress or motion to traverse—procedural tools that can exclude illegally obtained evidence or expose falsehoods in a warrant affidavit. These motions are some of the most powerful tools available to criminal defense attorneys in California.

What Is a Motion to Suppress?

A motion to suppress evidence is a formal request asking the court to exclude evidence that was obtained in violation of a defendant’s constitutional rights.

In California, this is governed by Penal Code §1538.5, which allows defendants to challenge the legality of searches, seizures, arrests, and detentions conducted by law enforcement.

If the court finds that the police violated the Fourth Amendment—or that the search did not fall within one of the recognized exceptions to the warrant requirement—then the evidence obtained as a result must be suppressed (excluded from trial). Without that evidence, the prosecution’s case may collapse entirely.

Common Grounds for a Motion to Suppress

Motions to suppress can arise from a wide range of law enforcement actions, including:

  1. Warrantless Searches:
    • Vehicle searches without probable cause
    • Searches of homes or property without a valid warrant or exigent circumstances
    • Personal searches without consent or lawful arrest
  2. Invalid or Overbroad Warrants:
    • Warrants issued without probable cause
    • Warrants lacking particularity about what is to be searched or seized
    • Warrants based on stale or unreliable information
  3. Illegal Detentions or Arrests:
    • Stops made without reasonable suspicion (violating Terry v. Ohio standards)
    • Arrests without probable cause
    • Unlawful extension of a traffic stop or detention
  4. Unlawful Consent Searches:
    • “Consent” obtained through coercion or under misleading circumstances
    • Consent given by someone without authority over the property
  5. Digital and Technological Violations:
    • Cellphone searches without a warrant
    • GPS tracking or geofence warrants not meeting probable cause standards
    • Unauthorized access to cloud data or social media content

If the police violated any of these constitutional protections, the evidence they obtained—drugs, weapons, statements, digital data, or other materials—can be excluded from use at trial.

What Is a Motion to Traverse a Search Warrant?

A motion to traverse is different from a motion to suppress. It attacks the truthfulness of the warrant affidavit itself—the sworn statement used by officers to convince a judge to issue the warrant in the first place.

If the defense can show that:

  1. The affidavit contains intentional or reckless false statements or omissions, and
  2. Those falsehoods were material to the finding of probable cause,

then the court must conduct what is called a Franks hearing (named after Franks v. Delaware, 438 U.S. 154). If the court agrees that the affidavit was misleading or dishonest, the search warrant will be invalidated, and all resulting evidence can be suppressed.

When Can These Motions Be Filed?

Under Penal Code §1538.5, motions to suppress can be filed at several stages of a case:

  • Preliminary Hearing: In felony cases before the information is filed.
  • Pretrial Motion: After the preliminary hearing or in misdemeanor cases before trial.
  • During Trial: In rare cases, a motion can be renewed if new grounds arise.

A motion to traverse is typically filed before trial, once the defense has obtained a copy of the warrant affidavit through discovery.

To prevail on a motion to suppress, the defense must show that:

  • The defendant had a reasonable expectation of privacy in the place searched or item seized.
  • The government’s intrusion was unreasonable under the Fourth Amendment.
  • No exception to the warrant requirement applies (e.g., consent, plain view, exigent circumstances, search incident to lawful arrest, inventory search, etc.).

For a motion to traverse, the burden is to show a substantial preliminary showing that the affiant intentionally or recklessly included false statements, or omitted material facts that would have changed the judge’s decision to issue the warrant.

Motion to Reconsider After a Denial

If a motion to suppress or traverse is denied in the trial court, the defense generally cannot proceed directly to appellate review. Under California Penal Code §1538.5(i) and related case law, the proper procedure is first to file a motion to reconsider the court’s ruling. This procedural step preserves the issue for further review and gives the trial judge an opportunity to correct or clarify the decision before a writ is filed in the Court of Appeal.

A motion to reconsider is typically based on one of two grounds: (1) new or different facts, circumstances, or law that were not presented at the initial hearing, or (2) legal or factual errors in the court’s ruling that materially affected the outcome. Examples include newly obtained discovery, inconsistencies revealed in officer testimony, or subsequent appellate decisions clarifying the relevant Fourth Amendment standard. The defense must act quickly—motions to reconsider must be filed within a reasonable time, usually before the case proceeds to trial.

Only after the motion to reconsider is ruled upon can defense counsel properly seek appellate relief through a writ of mandate or prohibition, challenging the denial of the suppression motion. Skipping this step can result in procedural forfeiture, making the issue unreviewable on appeal. In practice, an experienced defense attorney will use the reconsideration motion both to preserve appellate rights and to refine the factual and constitutional record for potential writ review.

Why These Motions Matter

Search-and-seizure law is one of the most intricate areas of criminal defense practice. A successful suppression or traverse motion can result in:

  • Dismissal of the case if the prosecution’s key evidence is excluded,
  • Suppression of statements obtained after an illegal search, and
  • Significant leverage in plea negotiations.

Even when suppression is denied, litigating these motions preserves constitutional issues for appeal and can reveal weaknesses in the state’s case.

Common Scenarios in California Cases

  1. Traffic Stops:
    Officers prolonging a stop beyond its lawful purpose to wait for K-9 units or search vehicles without probable cause.
  2. Home Searches:
    Officers entering a residence under “community caretaking” or “protective sweep” justifications that don’t withstand scrutiny.
  3. Warrant Affidavits:
    Detectives omitting exculpatory facts or relying on anonymous, unreliable informants.
  4. Cellphone Evidence:
    Accessing message content or location data without a properly limited warrant.
  5. Probation and Parole Searches:
    Officers exceeding the scope of a search condition or using it as a pretext for a general evidence-gathering expedition.

How Defense Attorneys Approach These Motions

A well-prepared motion to suppress or traverse involves:

  • Careful review of police reports, body-worn camera footage, and warrant affidavits
  • Legal research into Fourth Amendment and California precedents
  • Obtaining and cross-examining law enforcement witnesses at the hearing
  • Filing written briefs identifying each constitutional violation and requesting specific remedies

Success often depends on meticulous factual analysis and an understanding of how local judges interpret constitutional law.

In Summary

Motions to suppress and traverse are essential tools in protecting individual rights against unlawful police conduct. These motions safeguard the integrity of the justice system by ensuring that the ends do not justify unconstitutional means.

Whether the issue involves an invalid search warrant, an unlawful detention, or an overreach in a digital investigation, the constitutional principles are the same: evidence obtained in violation of your rights should not—and cannot—be used against you.

Consult a Criminal Defense Attorney Experienced in Suppression Motions

If your case involves evidence seized during a traffic stop, home search, or electronic data search, it is critical that your attorney scrutinize the legality of that search immediately. The attorneys at Radford & Rome, LLP are former prosecutors with extensive experience handling Fourth Amendment motions across Southern California courts. We know how to identify constitutional violations, draft persuasive suppression motions, and challenge defective warrants through traverse hearings. To discuss your case and determine whether a motion to suppress or traverse applies, contact Radford & Rome, LLP for a confidential consultation.