DE: Failure to file a pretrial motion to suppress is waiver with no plain error review

Failure to file a pretrial motion to suppress is waiver, and it will not be considered on plain error review, and for good reason. Swanson v. State, 2025 Del. LEXIS 504 (Dec. 31, 2025):

To be sure, it is well established that, although “[o]nly questions fairly presented to the trial court may be presented for review[],” in this Court, we may consider arguments not presented to the trial court if the interests of justice require it. Such a review, when allowed, proceeds under the plain-error standard. When we apply that standard, our review is limited to errors that affect substantial rights in a way that “jeopardize[s] the fairness and integrity of the trial process.” “[T]he doctrine of plain error is limited to material defects which are apparent on the face of the record; which are basic, serious and fundamental in their character, and which clearly deprive an accused of a substantial right, or which clearly show manifest injustice.”

In the context of this case, Swanson’s invocation of this doctrine is wide of the mark. It elides the fact that, by not moving before trial to suppress the fruits of the officer’s search, Swanson did not trigger the process by which our trial courts adjudicate such motions. That process involves a pretrial evidentiary hearing at which the trial court hears testimony and considers evidence relevant to the reasonableness of the challenged search or seizure. If the search or seizure was pursuant to a warrant, the defendant typically bears the burden of establishing the invalidity of the warrant. When, as here, the search and seizure was conducted without a warrant, the burden of proof is on the prosecution. Evidence that is relevant to the reasonableness of a search or seizure is frequently irrelevant and inadmissible at trial. Here, Swanson’s failure to move to suppress the challenged evidence before trial effectively precluded the State from establishing an evidentiary record that would support a finding by the trial court that the officers’ search of Swanson at the scene of his arrest was constitutionally permissible. Under these circumstances, it would be fundamentally unfair for this Court to consider Swanson’s Fourth Amendment claim.

Other reasons militate against allowing appellate review of a Fourth Amendment claim that was not raised before trial. Under 10 Del. C. § 9902, the State has an absolute right to appeal an order “suppressing or excluding substantial and material evidence, upon certification by the Attorney General that the evidence is essential to the prosecution[and] dismiss[al] of the complaint, indictment, or information or any count thereof to the proof of which the evidence suppressed or excluded is essential.” If the appellate court finds merit in the State’s appeal, the appellate court “shall reverse the dismissal, [and] the defendant may be subjected to trial.” If a trial court were to entertain a motion to suppress after jeopardy has attached, the State would lose its right to appeal an adverse ruling on suppression.

In addition to that, indiscriminate appellate review of suppression claims not raised in accordance with the trial court’s procedural rules could have undesirable practical effects. …