Suppression & Franks Hearings in Federal Court

Most federal evidence arrives through a warrant, and a warrant looks unassailable when you first read it. A judge signed it. It has a case number. It appears to be a finding.

What it actually is, is an argument — written by an agent, often quickly, summarising what other people said. Arguments contain gaps, and the Fourth Amendment provides a mechanism for testing them.

The deadline is the first thing that kills suppression motions

Under Rule 12(b)(3) a suppression motion must be raised before trial, and the district court sets a specific deadline in its scheduling order. Missing it generally waives the issue — including on appeal, where an unpreserved Fourth Amendment claim is reviewed, if at all, only for plain error.

This matters because suppression work is slow. It requires the full warrant application, the agent's reports, the underlying source material, and often an expert. That work cannot start the week the motion is due.

Standing: whose rights were violated

You can only suppress evidence obtained in violation of your own Fourth Amendment rights. The question is whether you had a reasonable expectation of privacy in the place searched. A passenger generally cannot challenge the search of someone else's car; an overnight guest generally can challenge the search of the home they are staying in.

Standing is where the government usually starts its response, and it is worth resolving early — an otherwise excellent motion fails entirely if the defendant has no privacy interest in the location.

The Franks hearing: attacking the affidavit itself

Under Franks v. Delaware, 438 U.S. 154 (1978), a warrant can be invalidated if the affidavit contained a false statement or a material omission. To get a hearing, the defense must make a substantial preliminary showing of two things:

1. The affiant — the officer who swore out the warrant affidavit — made a false statement, or omitted material information, knowingly and intentionally or with reckless disregard for the truth — negligence is not enough; and

2. The false statement or omission was necessary to the finding of probable cause. The test is whether, with the falsehood removed and the omission restored, what remains still establishes probable cause.

In practice the omission cases are stronger than the falsehood cases. Affidavits routinely leave out that the confidential informant was working off charges, that the informant had previously given unreliable information, that the surveillance did not actually corroborate what the tip claimed, or that a co-operator's account had shifted between interviews. Reconstructing what the magistrate was not told is the core of this work.

The good-faith exception, and getting past it

Even where a warrant is defective, United States v. Leon, 468 U.S. 897 (1984), often saves the evidence if officers relied on it in objectively reasonable good faith. This is the government's standard answer and it defeats a great many technically correct motions.

Leon itself identifies the situations where good faith does not apply: where the magistrate was misled by information the affiant knew or should have known was false; where the magistrate wholly abandoned the judicial role; where the affidavit is so lacking in indicia of probable cause that belief in its existence is entirely unreasonable; and where the warrant is so facially deficient that officers could not reasonably presume it valid.

Note the overlap: the first exception is the Franks ground. That is precisely why a deliberate-or-reckless falsehood theory is more valuable than a bare probable cause argument — it defeats good faith at the same time.

Warrantless searches and the exceptions the government relies on

Where there was no warrant, the government must fit the search into an exception. The recurring ones in federal practice are consent, whose voluntariness and scope are both contestable; automobile searches, which require probable cause; search incident to arrest; protective sweeps; inventory searches, which fail if not conducted under standardised policy; and exigent circumstances.

Border searches deserve particular attention in Texas. The border search exception is broad, and it extends to the functional equivalent of the border and to checkpoints — but its scope for forensic examination of electronic devices remains genuinely contested, and circuit law is not uniform.

Phones, location data, and cloud accounts

Riley v. California, 573 U.S. 373 (2014), requires a warrant to search a cell phone seized incident to arrest. Carpenter v. United States, 585 U.S. 296 (2018), requires a warrant for historical cell-site location information.

Beyond the threshold question of whether a warrant was needed, digital warrants raise a distinct particularity problem. A warrant authorising seizure of "all electronic devices and all data thereon" invites a general search of a person's entire life. Whether the warrant was adequately limited, and whether the search actually stayed inside those limits, are separate and often productive arguments.

Suppressing statements

Statement suppression rests on different grounds: Miranda where there was custodial interrogation without adequate warning or a valid waiver; voluntariness under the Fifth Amendment where the will was overborne; and the Sixth Amendment right to counsel once adversarial proceedings have begun.

The frequent battleground is whether the encounter was custodial at all. Agents commonly interview people at home or at work precisely so they can argue the person was free to leave and no warning was required. The details — how many agents, whether weapons were visible, whether the person was told they could decline, where in the house the interview happened — are what decide it.

Fruit of the poisonous tree — and the three exceptions

Evidence derived from an unlawful search is generally also suppressible under Wong Sun v. United States. The government's escape routes are independent source, where the evidence was also obtained lawfully and separately; inevitable discovery, where it would have been found anyway through lawful means; and attenuation, where the connection between the violation and the evidence has become sufficiently remote.

A well-built suppression motion therefore does two things: it identifies the original violation, and it traces every downstream item of evidence to it — because winning on the search but conceding the derivative evidence often changes very little.