What Happens at a Suppression Hearing

When the motion is filed

Suppression is generally decided before trial. In federal court, Rule 12(b)(3)(C) requires a motion to suppress to be raised before trial if its basis is reasonably available. The court can set a deadline. If it doesn’t, the deadline is the start of trial. A late motion is untimely, though the court may consider it for good cause.

Rule 12(b)(4)(B) also lets a federal defendant ask the government for notice of the evidence it intends to use, so that suppression motions can be made in time. State courts have their own rules and deadlines, which can be shorter. Knowing the deadline in your court is one of the first things to raise with an attorney.

What happens at the hearing

The judge decides the motion, not a jury. If the motion raises factual disputes, there may be an evidentiary hearing. Officers typically testify about what they knew and did, defense counsel cross-examines, and either side may offer records, video and other witnesses.

The Supreme Court has noted that “the rules of evidence normally applicable in criminal trials do not operate with full force at hearings before the judge to determine the admissibility of evidence” (United States v. Matlock, 1974). In federal court, Rule 12(d) requires the judge to decide pretrial motions before trial unless there’s good cause to defer, and to state the essential findings on the record when factual issues are involved.

Burden and standard of proof

In Matlock, the Court said “the controlling burden of proof at suppression hearings should impose no greater burden than proof by a preponderance of the evidence.” Which side carries the burden depends on the issue and the jurisdiction. For example, the prosecution bears the burden of showing that a confession following an illegal arrest is admissible (Brown v. Illinois), and of proving inevitable discovery by a preponderance of the evidence (Nix v. Williams). For other issues, such as standing, the burden often falls on the defendant. Rules vary, so the allocation in a given case is a question for local counsel.

Franks hearings on warrant affidavits

A warrant affidavit is usually presumed truthful. Under Franks v. Delaware (1978), a defendant can get a hearing to challenge it by making “a substantial preliminary showing” that a false statement was included “knowingly and intentionally, or with reckless disregard for the truth,” and that the statement was necessary to the finding of probable cause. In an ALPR case, the question might be whether the affidavit accurately described what a camera read actually showed.

If the defendant testifies

A defendant sometimes needs to testify at a suppression hearing, for example to show a privacy interest in a car. In Simmons v. United States (1968), the Supreme Court held that when a defendant testifies in support of a Fourth Amendment motion to suppress, that testimony “may not thereafter be admitted against him at trial on the issue of guilt unless he makes no objection.” Whether to testify is still a strategic decision to make with counsel.

ALPR records that may matter

What gets examined depends on the ground for the motion. In ALPR cases, it can include:

• The read record: the plate image, the plate text the software produced, the time and the camera location. See what data ALPR cameras collect.
• The alert and the hotlist entry behind it, including its source and when it was entered or updated. See hotlists and alerts.
• Dispatch audio, officer reports and video showing whether the alert was confirmed before the stop.
• Search and audit logs showing who queried stored data, when, and for what stated reason.
• The agency’s ALPR policy and any warrant or affidavit.

Some of these records exist only for a short time under retention policies, so they may need to be requested and preserved early.

After the ruling

If the motion is granted, the suppressed evidence generally can’t be used in the prosecution’s case at trial. What happens next depends on what evidence remains. If it’s denied, the case proceeds with the evidence in. Questions about the reliability of ALPR evidence, such as who was driving, can still be raised at trial. Appeal rights and timing after a suppression ruling differ by jurisdiction.