Severing Tainted Averments to Retest Probable Cause

Why Materiality Is the Decisive Prong

A Franks challenge has two halves: proving the affiant’s deliberate or reckless falsehood, and proving that the falsehood mattered. The second half — materiality — is where most cases are actually decided. Even a proven, intentional lie does not suppress anything if the affidavit still shows probable cause once the lie is removed.

The Fifth Circuit says so directly. In United States v. Cecil Brown, 298 F.3d 392 (5th Cir. 2002), the court explained that the second prong is often determinative: even if the defendant shows deliberate falsity or reckless disregard, he is not entitled to relief if, when the offending material is set to one side, the affidavit still contains enough to support probable cause. Materiality is measured by effect on the probable-cause finding, not by how egregious the misconduct was.

This is why a Franks motion is really an exercise in reconstruction. The court does not simply grade the officer’s honesty; it rebuilds the affidavit as it should have read and tests that version. Understanding exactly how that rebuild works — what comes out, what goes in, and how the remainder is judged — is the core of a severance argument, and it is the subject of the rest of this page.

The Reconstruction Test: Subtraction and Addition

The court rebuilds the affidavit in two complementary moves. For false statements it uses subtraction: it strikes the offending words and reads what is left. For omissions it uses addition: it inserts the material facts the affiant left out. The result is a single corrected affidavit that is then tested for probable cause.

Marks v. Hudson, 933 F.3d 481 (5th Cir. 2019), states the combined operation crisply: the court removes all plausibly claimed fabrications and inserts all plausibly claimed omissions to see whether the revised affidavit would still support the magistrate’s finding of probable cause. Both moves happen at once, so a challenge that pairs a false averment with a buried fact gets the benefit of both corrections. The table below shows the reconstruction applied to a hypothetical drug-house affidavit.

Only the challenged and omitted items change; the honest, unchallenged averments stay in. The retest is performed on that blended, corrected version — not on the original and not on a version stripped down to nothing.

Which Averments Get Cut

Severance is precise, not wholesale. The court removes the specific statement shown to be false, not every sentence connected to it. Deciding exactly how much to excise can be decisive, because a narrow cut may leave probable cause intact while a broader cut may destroy it.

United States v. Ortega, 854 F.3d 818 (5th Cir. 2017), illustrates the problem. There the affiant falsely claimed he personally received a tip from a reliable confidential informant, when he had actually gotten it secondhand through a translated relay. The court held that if the false statement was intentional or reckless, the reviewing court must excise the offending language and determine whether the remaining portion establishes probable cause. It noted the live question of how far the excision should reach — whether to cut only the false attribution or all of the informant-derived information — and found that once the false reliability vouching was removed, the excised affidavit was left with a bare tip stripped of any indication of the source’s reliability or history, which was insufficient for probable cause.

Ortega teaches two lessons for drafting a severance argument. First, identify the precise words that are false and press for excision of everything that depends on them — a false claim that a source was “reliable” often takes the source’s entire veracity with it. Second, connect the excision to the Gates framework: once the reliability vouching is gone, argue that the remaining tip lacks both veracity and basis of knowledge and therefore cannot carry a fair-probability finding on its own.

The breadth of the cut can be outcome-determinative, so it is worth litigating explicitly rather than leaving to the court. In Ortega the court flagged, without finally resolving, a recurring question: when an affiant falsely swears he personally received a tip from a proven, reliable informant, should the court excise only the false attribution, or all of the information traceable to that informant? The narrow cut leaves the tip standing, merely shorn of its pedigree; the broad cut removes the tip entirely. A defendant should press for the broader excision whenever the falsehood infects the reliability of the whole source, because a tip whose only claim to credibility has been proven false should not be treated as if it were independently trustworthy. Framing that argument — tying the scope of the cut to precisely what the false statement poisoned — is frequently where a severance motion is won or lost.

Retesting the Corrected Affidavit Under the Totality

Once the affidavit is rebuilt, the court applies the ordinary probable-cause standard to the corrected version. It makes a practical, common-sense decision whether, given all the circumstances in the corrected affidavit, there is a fair probability that evidence of a crime will be found in the place searched.

United States v. Kendrick, 980 F.3d 432 (5th Cir. 2020), lays out the full sequence: first determine whether the affidavit contains a false statement or material omission; then whether it was made intentionally or with reckless disregard; and finally, if the false statement is excised, whether the remaining content fails to establish probable cause. That last step is the totality retest, and Ortega confirms it borrows directly from Illinois v. Gates — the corrected affidavit is judged for a fair probability, weighing whatever veracity, basis of knowledge, and corroboration honestly remain.

The retest is holistic, not mechanical. The court does not simply count how many sentences survived; it asks whether what survived, read together, still adds up to probable cause. A corrected affidavit that retains independent, firsthand police observation of criminal activity may satisfy the standard even after a tainted informant paragraph is cut. A corrected affidavit whose only remaining support was the excised material will fail. The defense goal at this step is to show that the honest remainder, standing alone, describes nothing more than innocent or ambiguous activity.

When Severance Fails: Independent Surviving Content

Severance does not always win, and understanding why it fails is as important as knowing how it works. The warrant survives whenever the corrected affidavit retains enough independent, untainted content to support probable cause on its own. In that situation, the affiant’s dishonesty, however real, is legally immaterial.

Kendrick is the cautionary example. The defendant identified alleged falsehoods and omissions in the affidavit, but the Fifth Circuit held that probable cause still existed even with the challenged statements excised, because the remaining, reasonably trustworthy facts were sufficient under the totality of the circumstances to lead a prudent person to believe evidence would be found. Cecil Brown reached the same outcome on a wiretap affidavit: with the disputed material set aside, enough remained to establish probable cause, so no relief followed. In both cases the second prong, not the first, ended the inquiry.

The practical takeaway is to attack the load-bearing averments, not the decorative ones. If the affidavit rests on several independent pillars — an informant tip, corroborating surveillance, and a defendant’s recorded admission — knocking out one pillar rarely topples the warrant. A severance argument succeeds only when the challenged statements were doing the real work of the probable-cause showing, so that their removal leaves the corrected affidavit describing innocent conduct or unsupported suspicion. Choosing the target is therefore a strategic judgment made before the motion is ever filed.

Building the Reconstruction Into the Motion

Because the court will perform the reconstruction anyway, the strongest motions perform it first and hand the court the finished analysis. Rather than merely alleging that the affiant lied, effective practice sets out the corrected affidavit on the page — showing exactly what is cut, what is added, and what honestly remains — then argues that the remainder cannot support probable cause.

This approach carries the defendant’s burden at both stages of a Franks case at once. It satisfies the necessity requirement of the preliminary showing by demonstrating that the challenged statement was essential to probable cause, and it frames the ultimate merits question in the light most favorable to suppression. It also disciplines the theory: if counsel cannot write a corrected affidavit that fails on probable cause, the motion is not yet ready, because the court’s own reconstruction will reach the same conclusion.

Two drafting habits help. First, quote the affidavit precisely and mark each challenged line, so the excision is unmistakable and narrow disputes about wording do not swallow the motion. Second, tie every proposed cut and insertion to the record — the discovery, reports, and declarations that prove falsity or the omitted fact — because the retest is only as strong as the proof behind each correction. A reconstruction grounded in the record gives the court a clean path to the conclusion that, told the truth, the magistrate could not have found probable cause. That is the whole object of severing tainted averments.

When the Government Concedes Falsity and Fights Materiality

In many Franks cases the government does not defend the affiant’s statement at all. It concedes, at least for argument, that the line was false or the fact was omitted, and stakes everything on the second prong — arguing that the corrected affidavit still shows probable cause. That posture turns the case into a pure materiality fight.

This follows naturally from the rule that the second prong is often determinative. Rather than litigate the officer’s state of mind, prosecutors frequently assume falsity and move straight to reconstruction, urging the court to find that untainted averments — independent surveillance, a defendant’s recorded statement, seized physical evidence — carry probable cause without the challenged material. Kendrick and Cecil Brown both resolved that way: the courts set the disputed material to one side and found the remainder sufficient, so they never had to decide whether the affiant acted with reckless disregard. For the government, conceding the point it would likely lose and winning on the point it can defend is efficient advocacy.

For the defense, that posture is a warning about target selection. If the prosecution can win by conceding the lie, then the lie was never load-bearing, and the motion was aimed at the wrong averment. The answer is to build the challenge around the statements the affidavit cannot spare, and to attack the supposedly independent survivors as well — showing that the “corroborating” surveillance was innocuous, that the recorded statement is ambiguous, or that the remaining facts describe conduct as consistent with innocence as with crime. A materiality fight is won by shrinking the honest remainder until it can no longer support a fair probability, not by proving the officer dishonest.

Anticipating the concession also shapes the written motion. Because the court will almost certainly perform the reconstruction, the defense should present its own corrected affidavit and then walk through each surviving averment, explaining why the remainder falls short even taken at face value. Meeting the government on the second prong directly — rather than dwelling on the affiant’s intent the prosecution has already conceded — puts the defense argument exactly where the decision will be made. The cases that suppress evidence are the ones in which the challenged statements were doing the real work, and the defense proved it by showing what honestly remained could not.

Where This Fits

This guide is one of four situations that arise under the Franks Motion / Franks Hearing. Start with the parent motion for the overall framework, or move to a related fact pattern:

What the Case Law Says

These decisions—verified against primary sources—control how this issue is litigated. Every case still turns on its own facts.

• United States v. Ortega, 854 F.3d 818 (5th Cir. 2017) — A court excises the intentional or reckless false statement and retests the remaining affidavit; a bare tip stripped of reliability failed probable cause.
• United States v. Kendrick, 980 F.3d 432 (5th Cir. 2020) — Applying the three-step test, probable cause survived because the excised affidavit's remaining trustworthy facts still supported a fair probability of evidence.
• Marks v. Hudson, 933 F.3d 481 (5th Cir. 2019) — The court removes all plausibly claimed fabrications and inserts all plausibly claimed omissions, then asks whether the revised affidavit still supports probable cause.
• United States v. Cecil Brown, 298 F.3d 392 (5th Cir. 2002) — The second prong is often determinative; even with deliberate falsity, no relief if remaining content still supports probable cause.

General summaries of published opinions for information only — not predictions about any specific case.