Swanson v. State: Rule 12 Waiver Bars Plain-Error Review of Untimely Fourth Amendment Suppression Claims Absent Cause

Court: Supreme Court of Delaware | Date: December 31, 2025 | Disposition: Affirmed

1. Introduction

Swanson v. State confronts a recurring appellate posture: a defendant seeks Fourth Amendment relief on appeal despite never filing a pretrial motion to suppress and never objecting at trial. Kenneth Swanson was arrested on outstanding capiases and, after a patdown and retrieval from inside his pants, police recovered a knotted bag later confirmed to contain approximately 27 grams of cocaine. Swanson was convicted (after a bench trial) of Tier 3 cocaine possession and sentenced as a habitual offender under 11 Del. C. § 4214(a).

The central issue was not whether the search was reasonable under the Fourth Amendment on the merits, but whether the Delaware Supreme Court should review the unpreserved suppression claim at all—particularly under “plain error”—given Superior Court Criminal Rule 12’s requirement that suppression motions “must be made prior to trial,” and its express waiver provision absent “cause shown.”

2. Summary of the Opinion

The Court affirmed and declined to reach the Fourth Amendment question. It held that Superior Court Criminal Rule 12 “means what it says”: motions to suppress must be made before trial; failure to do so, absent cause, constitutes waiver; and, in these circumstances, waiver displaces plain-error review. The Court emphasized the structural and fairness problems that arise when a suppression claim is raised for the first time on appeal: the State is deprived of its opportunity (and burden) to develop a suppression record at a pretrial evidentiary hearing, and trial judges are not required to sua sponte police suppression issues during trial.

The Court acknowledged some prior Delaware decisions that had proceeded to plain-error review despite the absence of a pretrial suppression motion, but read those cases narrowly and rejected any notion that appellate plain-error review is mandatory in this posture. The Court aligned Delaware’s approach with the majority rule in the federal circuits enforcing Federal Criminal Rule 12’s timeliness regime for suppression issues.

3. Analysis

3.1. Precedents Cited

A. Delaware authorities on plain error and preservation

Wainwright v. State, 504 A.2d 1096 (Del. 1986): The Court quoted Wainwright for the controlling articulation of plain error: errors must be fundamental, apparent on the face of the record, and so serious as to jeopardize the fairness and integrity of the process. In Swanson, that strict standard did not “open the door” because the antecedent problem was procedural waiver under Rule 12 and the absence of a suppression record.
Mills v. State, 947 A.2d 1122, 2007 WL 4245464 (Del. Dec. 3, 2007) (TABLE); Jones v. State, 882 A.2d 761, 2005 WL 2473789 (Del. August 22, 2005) (TABLE); Walley v. State, 622 A.2d 1097, 1993 WL 78221 (Del. Mar. 17, 1993) (TABLE): These cases were cited for the observation that, without a pretrial suppression motion, an adequate record is often lacking to review a suppression claim. The Swanson Court acknowledged that in some of those cases it nonetheless performed plain-error review, but clarified they do not establish a rule compelling plain-error review whenever Rule 12 was ignored.
Supr. Ct. R. 8: The Court reiterated Delaware’s baseline appellate principle: only issues fairly presented below are reviewable, subject to the narrow interests-of-justice/plain-error safety valve—one that does not override Rule 12’s suppression framework absent cause.

B. Delaware authorities on suppression burdens and review posture

State v. Sisson, 883 A.2d 868 (Del. Super. Ct. 2005): Cited for the burden principle that when a search is pursuant to a warrant, the defendant typically bears the burden to establish invalidity—an allocation that underscores why the suppression forum matters and why record-development is central.
Juliano v. State, 254 A.3d 369 (Del. 2020) (quoting Hunter v. State, 783 A.2d 558 (Del. 2001)): Cited for the complementary rule that when the police act without a warrant, the burden of proof is on the prosecution to justify the search. Swanson uses this to highlight the unfairness of allowing a defendant to bypass a suppression hearing—where the State would have carried that burden— and then complain on appeal that the State failed to satisfy it.
Buckham v. State, 185 A.3d 1 (Del. 2018) (quoting Sisson v. State, 903 A.2d 288 (Del. 2006)): Invoked to preserve a narrow potential avenue for review where the relevant record is confined to the “four corners” of a warrant, making appellate review less dependent on facts that would have been developed at a suppression hearing. The Court expressly “leave[s] the door open” in that limited context.

C. Federal authorities on Rule 12 consequences for untimely suppression claims

United States v. Chavez-Valencia, 116 F.3d 127 (5th Cir. 1997): The Court relied on this decision’s policy analysis: allowing appellate review of unraised suppression claims imposes systemic costs by encouraging the government to forgo developing evidence it otherwise would have introduced and then forcing it to defend on an underdeveloped record.
United States v. Whitten, 706 F.2d 1000 (9th Cir. 1983): Cited for the general principle and rationale that suppression issues should be presented first to the trial judge to avoid surprise, permit evidence-taking, and promote judicial economy.
The Court also cited numerous circuit decisions reflecting the majority federal approach enforcing Rule 12 suppression timeliness: United States v. Luciano, United States v. Martinez, United States v. Sok, United States v. Martinez-Hidalgo, United States v. Randolph, United States v. Ibarra-Zelaya, United States v. Obiukwu, United States v. McMillian, United States v. Green, United States v. Dirden, and United States v. Pou. Collectively, these cases supplied comparative authority supporting Delaware’s insistence that suppression be litigated in the designated pretrial channel.
United States v. Ford, 34 F.3d 992 (11th Cir. 1994): Used to underscore a distinct institutional concern: if suppression is litigated after jeopardy attaches, the State may lose its opportunity to appeal an adverse suppression ruling (a concern Delaware parallels via statute).

D. Statutory structure supporting the Court’s institutional concerns

10 Del. C. § 9902: The Court emphasized that the State has an absolute right to appeal a pretrial suppression order under specified conditions. Allowing suppression litigation after jeopardy attaches would functionally erode that statutory right and distort the procedural architecture of criminal adjudication.

3.2. Legal Reasoning

Core holding: Rule 12’s suppression timing and waiver provisions govern; absent “cause shown,” an untimely suppression claim is waived and is not resurrected by plain-error review.

The Court’s reasoning proceeds in three interlocking steps:

Rule 12 allocates the forum and timing for suppression litigation. Suppression issues are “capable of determination without the trial of the general issue” and therefore belong in pretrial motion practice. Rule 12 further singles out suppression motions as those that “must be raised before trial,” and states that failure “shall constitute waiver,” with relief only “for cause shown.”
Permitting plain-error review would defeat Rule 12’s evidentiary design. Suppression litigation requires a dedicated pretrial evidentiary hearing where the trial court can receive evidence on reasonableness. This is particularly acute in warrantless-search cases because the State bears the burden (Juliano/Hunter). By not filing, Swanson foreclosed the mechanism through which the State would have created a record to carry that burden (e.g., facts about officer safety, privacy steps taken, exposure to the public, the necessity of the method used, etc.). The Court treated it as “fundamentally unfair” to fault the State on appeal for not proving reasonableness in a record the defense prevented from being built.
Institutional and practical consequences counsel against after-the-fact review. Two highlighted consequences are: (a) risking impairment of the State’s statutory right to appeal suppression rulings (10 Del. C. § 9902) if suppression is litigated after jeopardy; and (b) placing trial judges in an “untenable position” if they were expected to sua sponte suppress evidence mid-trial based on issues neither litigated nor required elements of the State’s proof.

The Court then reconciled its own past practice: while it had sometimes applied plain-error review in similar circumstances, it framed those instances as discretionary rather than mandatory and reaffirmed that a “straightforward application” of Rule 12 supports waiver here.

Finally, the Court gave content to the “cause shown” safety valve and delineated a narrow carve-out:

Cause may exist where information supporting suppression “arose too late” to permit a timely motion (citing United States v. Sok).
Possible plain-error review remains in warrant cases confined to the “four corners” of the warrant (citing Buckham v. State), because review in that setting is less dependent on extra-record fact development typical of warrantless-search disputes.

3.3. Impact

Doctrinal impact in Delaware: Swanson clarifies that Rule 12 waiver is not merely a factor in whether plain-error review is granted; it is a controlling procedural bar absent cause. This shifts Delaware appellate expectations in suppression contexts from “sometimes reviewed for plain error” toward “generally not reviewed,” aligning Delaware more openly with the dominant federal approach.

Practical impact on defense and prosecution:

Defense counsel must treat suppression as a pretrial obligation, not a trial objection issue. A tactical choice to forgo suppression litigation will likely be treated as a binding waiver on appeal unless “cause” is shown.
Prosecutors can rely more confidently on Rule 12’s channeling function, preparing suppression records when motions are filed rather than anticipating sua sponte trial-court intervention or post hoc appellate review.

Trial-court administration: The decision reinforces a clear division of labor: suppression determinations belong to pretrial hearings; the trial itself concerns adjudication of guilt on the charged elements, not retrospective constitutional audits of evidence-gathering absent a litigated motion.

4. Complex Concepts Simplified

“Motion to suppress”: A request—usually litigated before trial—to exclude evidence obtained in violation of constitutional protections (here, the Fourth Amendment).
Rule 12 “waiver” vs. “plain error”:
- Waiver (Rule 12) here means a procedural forfeiture: if you do not timely file a required suppression motion, you generally lose the issue.
- Plain error is a narrow appellate safety valve for fundamental mistakes apparent on the record that threaten the fairness and integrity of proceedings. Swanson holds it does not ordinarily override Rule 12’s suppression waiver absent cause.
“Cause shown”: A recognized justification for missing the Rule 12 deadline—e.g., the facts needed to support suppression were not reasonably available before trial. Without a showing of cause, appellate courts will not rescue the issue.
Why record development matters in warrantless searches: The State bears the burden to justify a warrantless search. That justification often turns on details (privacy precautions, safety concerns, exigency, availability of less intrusive methods) that are not trial elements and may never surface without a suppression hearing.
“Jeopardy has attached”: The point in a criminal case (typically when a jury is sworn or, in a bench trial, when the first witness is sworn) after which certain protections limit retrials and can affect appeal rights—here, relevant to preserving the State’s statutory suppression-appeal pathway.

5. Conclusion

Swanson v. State establishes a clear Delaware rule of appellate restraint: when a defendant fails to file a required pretrial motion to suppress and shows no “cause” for that failure, Rule 12’s waiver provision forecloses appellate review—including plain-error review—of a Fourth Amendment suppression claim raised for the first time on appeal.

The decision is significant not because it expands or contracts substantive Fourth Amendment doctrine, but because it fortifies the procedural architecture that determines when and how Fourth Amendment disputes are litigated. By insisting that suppression questions be raised in the pretrial forum designed to develop a factual record and protect reciprocal rights (including the State’s appeal right), Swanson promotes orderly adjudication, reduces appellate fact-finding in constitutional disputes, and places primary responsibility for suppression litigation where Rule 12 has always placed it: in timely pretrial motion practice.