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The Importance of a Probable Cause Affidavit in Texas Criminal Defense

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For the general public, learning about probable cause affidavits in criminal matters often comes from news stories of court orders sealing the affidavit from public view in high-profile cases.  Two recent examples:  first, the ongoing media coverage of a probable cause affidavit alleging criminal acts that led to a federal search warrant being issued of the Trump residence in Palm Beach, Florida (“Mar-a-Lago”).  For more, read “Affidavit Supporting a Warrant for Mar-a-Lago Search Will Not Be Made Public,” written by Saul Martinez and published by The New York Times on August 11, 2022, and “Mar-a-Lago Affidavit Is Unsealed with Redactions — 38 Pages of Background Establish Probable Cause for Search,” written by Kyler Alvord and published by People on August 26, 2022.

A second example:  the redacted probable cause affidavit released on November 29, 2022, in the “Delphi Killer” case that allowed Indiana police to arrest Richard Allen for the 2017 murders of Liberty German and Abigail Williams in Delphi, Indiana.  Read, “Why the Delphi murders court records are sealed; suspect Richard Allen requests bail,” written by Arleigh Rodgers and Rick Callahan / Associated Press and published by ABC7-Chicago on November 21, 2022, and “Unsealed Affidavit Sheds Light on Delphi, Indiana Killings,” written by Katie Smith and published by News Nation Now on November 29, 2022.

Of course, for those being investigated, arrested, or charged by law enforcement at either the state or federal level, probable cause affidavits are more than true crime curiosities.  There is a great power to be unleashed by a probable cause affidavit: based upon the statements of a single officer or agent, individuals can lose their freedom as well as their right to privacy in a search and seizure.

From a criminal defense lawyer’s viewpoint, it is foolhardy to underestimate the importance of the probable cause affidavit in any felony matter.  It may well be the key to the entirety of the defense’s case.

What is a Probable Cause Affidavit?

Here in Texas, both federal and state constitutional provisions protect against property being taken by the authorities or any arrests being made without proper protection of individual freedoms.  The core protection involves “probable cause,” which must be shown before any police action can be taken for either an arrest or a search.

See U.S. Const., Amend IV (“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized”); TEX. Const. art. I, § 9 (“[N]o warrant to search any place, or to seize any person or thing, shall issue without describing them as near as may be, nor without probable cause, supported by oath or affirmation“); and Tex. Code Crim. Proc. art. 1.06, 18.01(b) (“A sworn affidavit setting forth substantial facts establishing probable cause shall be filed in every instance in which a search warrant is requested“).

In sum, probable cause affidavits are sworn statements of a law enforcement officer (think Dallas Police officer, Texas Ranger, or Federal Bureau of Investigation agent) that detail that single individual’s reasons or beliefs that the constitutional protections have been respected and that there are sufficient grounds to arrest someone for a violation of criminal law or to search his or her property and seize items that may be used as evidence of an offense.

Form of the Probable Cause Affidavit

From a procedural perspective, they must meet the requirements of any affidavit under the law.  There must be a signature by the affiant.  There must be an affiant’s oath as to its veracity.  That oath must involve a personal appearance by the officer where he or she swears to the truth of the document’s statements and signs before the proper official.  From the Texas Court of Criminal Appeals: “…[it] has held for the better part of a hundred years that, before a written statement in support of a search warrant will constitute a `sworn affidavit,’ the necessary oath must be administered `before’ a magistrate or other qualified officer.” Clay v. State, 391 S.W.3d 94, 98-99 (Tex. Crim. App. 2013).

Substance of the Probable Cause Affidavit

Fundamentally, the probable cause affidavit must have sufficient substance.  It must provide a reasonable basis for believing there has been a crime perpetrated by the accused before an arrest can be made.  It must have reasonable grounds to show there has been a violation of the criminal laws before someone’s car, home, boat, office, etc., can be subjected to a search and possible seizure of property.

There are occasions where a probable cause affidavit can go so far as to allow a warrantless search and seizure or a warrantless arrest.  Here, there is an arrest or search without any judge first reviewing the affidavit and confirming sufficient bases exist for the police action by the signing of a warrant.  Warrantless probable cause affidavits must be especially clear in the totality of their described circumstances to support this unilateral action by law enforcement – particularly in serious felony matters.

Flaws in a Probable Cause Affidavit: Defense Challenges

Today, there are forms used by most law enforcement agencies (state and federal) that are blank affidavits ready to be completed by the individual officer.  An example of a Harris County probable cause affidavit form can be seen online here.

Simply filling out an affidavit form and presenting it to the court places tremendous power in the hands of a single law enforcement officer.  Understandably, these forms include directions to be followed in order to minimize errors and constitutional due process violations.  However, these forms do not guarantee that the accused’s rights will be protected.

An experienced criminal defense attorney will review the elements of the affidavit from a procedural perspective even if a form has been used.  It is shocking how often basic procedural requirements are not followed in a probable cause affidavit involving felony allegations.

Consider the case of Wheeler v. State, 573 S.W.3d 437 (Tex. App.-Fort Worth 2019).  In Wheeler, a police officer arrested Chase Wheeler for driving while intoxicated.  Since Mr. Wheeler refused to be tested at the scene for driving drunk (e.g., field sobriety, breath test, etc.), he was taken to the police department so a search warrant could be obtained to take his blood.  The police officer used a probable cause affidavit form to support his request for that warrant.

Problem was, that officer did not take the oath and swear to that probable cause affidavit.  The Texas Court of Criminal Appeals affirmed the judgment of the court of appeals which approved the defense’s motion to suppress that affidavit and throw out the evidence obtained in the search.  From the High Court: “…[t]here is no question that the officer’s failure to take the oath and swear to his probable-cause affidavit was improper.” Id.

The Good Faith Exception of TCCP art. 38.23(b)

Under Texas law, officers must “…  act in objective good faith reliance upon a warrant issued by a neutral magistrate based on probable cause.”  Tex. Code of Crim. Proc. Art. 38.23(b).  The prosecution argued the officer’s failure to swear to the probable cause affidavit in Wheeler’s case was a simple mistake, and a “good faith exception” should be applied in the case.  This argument was defeated by the defense.

It was held and affirmed that the police officer must act in objective good faith, and this means that a reasonable police officer in the same position would have believed the warrant was valid.  Wheeler, 626 S.W.3d at 863, citing McClintock v. State, 541 S.W.3d 63, 73 (Tex. Crim. App. 2017).  Because of the “critical nature of a sworn probable-cause affidavit to support issuance of a search warrant,” the good faith exception did not apply.  Subjective good faith is not enough.  Id.   A police officer knows, or reasonably should know, that even an affidavit form must be properly signed and sworn in order to be constitutionally valid.

As the Court of Criminal Appeals explains:

“Applying the statute’s requirement of objective good faith to the situation at hand, we conclude that no objectively-reasonable police officer would have believed that the warrant here was valid when it was knowingly obtained by an unsworn probable-cause affidavit. In fact, it was wholly unreasonable for any officer in Officer Bonner’s shoes to believe that there was no need to attest to a probable-cause affidavit when: (1) the oath requirement has been a constitutional mandate for all law enforcement officers for well over a century; (2) the Texas Legislature has codified and repeatedly emphasized the oath requirement in the Code of Criminal Procedure; (3) this Court’s opinions have consistently held that the oath requirement is critical to obtaining a search warrant; (4) law enforcement officers are taught in the police academy that they must swear to the truthfulness of their probable-cause affidavits before a magistrate or other qualified person; and (5) the forms used by Officer Bonner in this case for the probable-cause affidavit and search warrant both refer to the oath requirement and state that the documents were “verified” and/or “sworn before” a magistrate.”  

Wheeler, 626 S.W.3d at 863-4.

The Statements Within the Probable Cause Affidavit

After reviewing the form and procedural aspects of a probable cause affidavit, the power of the words contained in the affidavit itself must be considered by the defense attorney.  What does this officer assert are sufficient grounds to take someone’s freedom — potentially harming their reputations, careers, finances, and families — or to grab their personal property and take it away from homes, cars, etc.?

There is no constitutional definition of “probable cause” in the state or federal constitutions.  Instead, courts have held probable cause is found when the facts stated in the affidavit are “…sufficient in themselves to warrant a man of reasonable caution in the belief that an offense has been or is being committed.” Brinegar v. United States, 338 U.S. 160, 176-77, 69 S. Ct. 1302, 93 L. Ed. 1879 (1949).

Four Corners of the Probable Cause Affidavit

Courts give the judge or magistrate who reviews the probable cause affidavit and approves the warrant great deference.  Nevertheless, the defense can request judicial review of that determination by a higher court, where the court will be “bound by the four corners of the affidavit” in order to confirm that there was, indeed, probable cause and a “substantial basis” to act. Illinois v. Gates, 462 U.S. 213, 238, 103 S.Ct. 2317, 76 L.Ed.2d 527 (1983); State v. McLain, 337 S.W.3d 268, 272 (Tex.Crim.App. 2011).

The probable cause affidavit can include hearsay, for instance.  (Consider the hearsay admittedly included in the recently released Delphi Killer probable cause affidavit as an example.)  Hearsay is not admissible evidence.  Can it be successfully challenged in the probable cause affidavit?

This was achieved in the case of State v. Duarte, 389 S.W.3d 349 (Tex. Crim. App. 2012).  A two-page probable cause affidavit signed by a San Antonio police detective was approved by the magistrate but found lacking upon judicial review.  The defense motion to suppress was granted, and affirmed on appeal, because the affidavit had nothing to verify and confirm that the hearsay statements provided by the police informer were true and accurate.

From the High Court:

We agree with the State that “an affiant’s basis for finding the informant reliable need not be of any certain nature.” But, whatever its nature, it must be demonstrated within the four corners of the affidavit. Here, the affiant-officer believed that the confidential informant was credible largely because he was a “confidential informant” — a “snitch” with pending criminal charges who wanted to trade a tip for leniency. We decline to equate the reliability of a first-time, unnamed informant with that of a named citizen-informant.

The trial judge correctly identified the problem with this boilerplate affidavit: it contained insufficient particularized facts about appellee’s alleged possession to allow the magistrate to determine probable cause to issue a search warrant. The trial judge did not err in granting Mr. Duarte’s motion to suppress.

Duarte, 389 S.W.3d at 360.

Defending Against Probable Cause Affidavits

Probable cause affidavits are important because they are very powerful tools available for use by a single law enforcement officer.  While constitutional protections exist to try and protect individuals from overreaching police power and violations of due process, criminal defense lawyers know the power of these documents and how they can result in loss of livelihoods, social stigmas, destruction of relationships, and other harms to a someone who is accused but innocent of the charges.

An arrest can permanently harm someone as well as their loved ones. A probable cause affidavit has the power to cause this harm, and it is the tool of one person in a position of authority.

The tendency of law enforcement is to arrest.  An experienced and savvy criminal defense attorney respects the power of the probable cause affidavit as well as its flaws.  Motions to suppress can be filed, and in some instances, a successful challenge to a probable cause affidavit can result in the entire case being dismissed. See, What is a Motion to Suppress?

For more, read:


For more information, check out our web resources, read Michael Lowe’s Case Results, and read his in-depth article,” Pre-Arrest Criminal Investigations.”

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