K9 Marijuana Alerts and Ambiguous “Gun” References After Hemp Legalization:
A Commentary on United States v. Saine (6th Cir. 2025)

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I. Introduction

In United States v. Ricco Saine, No. 24‑5638 (6th Cir. Dec. 22, 2025), the Sixth Circuit addresses two increasingly common issues in contemporary criminal practice:

1. Whether a drug-detection dog’s alert still provides probable cause to search a vehicle when the dog cannot distinguish between illegal marijuana and now-legal hemp or other legal cannabis derivatives.
2. Whether a text message stating “I’ve got your gun and stuff in the house” is inadmissible propensity evidence under Federal Rule of Evidence 404(b) when the government charges the defendant with possessing specific firearms.

The case arises from a motel parking-lot encounter in Tennessee, a subsequent K9 sniff and search uncovering a firearm, and later investigative steps uncovering additional firearms at the defendant’s shared home with his wife, Tonya. The defendant, a convicted felon, was prosecuted for two counts of unlawful firearm possession under 18 U.S.C. § 922(g)(1).

The opinion, authored by Judge Bloomekatz for a unanimous panel, is recommended for publication and thus binding within the Sixth Circuit. It articulates two important clarifications:

• A canine alert to marijuana remains a strong basis for probable cause even in a jurisdiction where hemp and some cannabis products are legal—at least on the record presented.
• A text message referencing “your gun,” used to show the defendant’s knowledge of firearms at a location, is not classic “other-acts” evidence under Rule 404(b), and is admissible (with or without 404(b) analysis) so long as its probative value is not substantially outweighed by unfair prejudice.

Together, these holdings provide important guidance on the intersection of evolving cannabis laws with Fourth Amendment doctrine, and on the treatment of ambiguous references to firearms under the Federal Rules of Evidence.

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II. Summary of the Opinion

The court affirms Saine’s convictions on both counts of felon-in-possession of a firearm.

A. Fourth Amendment / Motion to Suppress

Saine moved to suppress a firearm found in his truck after a K9 alerted to the vehicle. The dog was trained to detect marijuana and several other illegal drugs, but could not distinguish marijuana from legal hemp or certain legal cannabis byproducts. Tennessee law at the time:

• Criminalized marijuana,
• Legalized hemp,
• Legalized certain byproducts of the marijuana plant.

On appeal, Saine argued that the dog’s inability to distinguish legal from illegal cannabis meant the alert did not provide probable cause.

The Sixth Circuit rejected this argument. Relying on Florida v. Harris, 568 U.S. 237 (2013), and other precedents, the court held that probable cause is based on probabilities, not certainties, and does not require officers to rule out every innocent explanation. A K9 alert can still create a “fair probability” of contraband even in a partial-legalization environment, particularly when reinforced by contextual facts such as:

• The motel’s status as a “known hot bed of criminal activity” and drug crimes;
• A BOLO indicating Saine was suspected of narcotics trafficking; and
• The dog’s training and certification to detect illegal narcotics.

Given the totality of the circumstances, the court held there was probable cause to search Saine’s truck, and the district court correctly denied the motion to suppress.

B. Evidence / Rule 404(b) and Text Messages

In addition to the motel firearm (the Ruger), the government charged Saine with possessing two firearms found at his and Tonya’s house: a Walther PK380 pistol and a Springfield 5.56 rifle. As part of that proof, the government introduced a text exchange:

Tonya: “I’ve got your gun and stuff in the house”
Saine: “K”

Saine objected at trial that this message was hearsay and was also inadmissible under Rule 404(b) as improper propensity evidence—especially since the text did not expressly specify which firearm it referenced and could conceivably refer to an uncharged gun. The district court admitted the texts as proof of Saine’s knowledge and declined to exclude them under 404(b), offering a limiting instruction that defense counsel rejected.

On appeal, Saine argued that the lack of explicit linkage between “your gun” and the indicted firearms meant the messages functioned as other-acts evidence (implying prior firearm possession) and thus improperly invited a propensity reasoning: he possessed a gun before, so he likely possessed these.

The Sixth Circuit held:

• The evidence was admitted to show Saine’s knowledge (state of mind) about firearms in the home, not to prove an “other bad act” for propensity, so Rule 404(b)(1) was not even the right framework.
• The district court acted within its discretion by admitting the text exchange for this permissible purpose; the possibility that the message referred to a different firearm went to the weight of the evidence, not to its admissibility.
• Even assuming Rule 404(b) applied, there was sufficient evidence for a jury to find that “your gun” referred to the Walther and/or Springfield, and the probative value was not substantially outweighed by any risk of unfair prejudice under Rule 403.

Accordingly, the text messages were properly admitted, and the conviction stands.

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III. Detailed Analysis

I. Factual and Procedural Background

A. The Motel Encounter and K9 Search

In August 2021, Officer Blevins approached Saine next to his truck in a motel parking lot in Tennessee. The encounter was guided by:

• A BOLO (Be On the Lookout) suggesting Saine was suspected of narcotics trafficking; and
• Blevins’s knowledge that the motel was a “known hot bed of criminal activity,” including drug offenses.

Blevins requested a K9 unit. About ten minutes later, Officer Bates arrived with a narcotics-detection dog certified to detect methamphetamine, cocaine, heroin, and marijuana. The dog was not trained to distinguish between:

• Illegal marijuana, and
• Legal hemp and certain marijuana byproducts lawful under Tennessee law.

The K9 alerted at the driver’s side rear door of the truck. Officers searched the truck and found:

• A small amount of plant material believed to be marijuana (its actual identity was not established in the record), and
• An unzipped bag containing a Ruger EC9S 9mm pistol and Saine’s ID.

B. Discovery of Additional Firearms at the Home

Weeks later, Officer Slater visited the home shared by Saine and Tonya. Saine was not present. Tonya showed and claimed ownership of three firearms:

• A Walther PK380 pistol (the “Walther”);
• A Springfield Saint 5.56 rifle (the “Springfield”); and
• Another pistol (not charged in this case).

Slater later obtained surveillance footage from a gun store showing Tonya purchasing the Walther and Springfield while accompanied by Saine.

About a month later, Saine was arrested on unrelated charges. While in custody, he attempted to negotiate with Officer Slater, offering to have Tonya “hand over his AR-15” if Slater would help secure his release. Around this time, officers seized the Walther and the Springfield from the couple’s home and, pursuant to a warrant, searched Saine’s cellphone. The phone contained the text exchange quoted above in which Tonya wrote “I’ve got your gun and stuff in the house,” to which Saine replied “K.” The texts were sent:

• Eight days after Tonya purchased the Walther and Springfield; and
• Three days before officers recovered those firearms from the home.

C. Indictment, Suppression Motion, and Trial

The federal indictment charged Saine with two counts of being a felon in possession of firearms under 18 U.S.C. §§ 922(g)(1), 924(e)(1):

1. Possession of the Ruger seized from his truck (Count One);
2. Possession of the Walther and Springfield seized from his home (Count Two).

Saine moved to suppress the Ruger, challenging the lawfulness of the K9-based search. At the suppression hearing, he emphasized that the K9 could not differentiate hemp from illegal marijuana, asserting that this undermined probable cause. The district court, relying on Florida v. Harris, rejected that argument and denied the motion.

At trial, Saine objected to admission of the text exchange:

• As hearsay, and
• As propensity evidence barred by Rule 404(b).

The district court admitted the text for the non-hearsay purpose of showing Saine’s knowledge (state of mind) about the presence of a gun at the home. The court offered a limiting instruction, which defense counsel declined. The jury convicted Saine on both counts.

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II. Fourth Amendment Holding: K9 Alerts and Partial Legalization of Cannabis

A. Precedents and Doctrinal Context

1. The Automobile Exception and Probable Cause

Under the “automobile exception” to the Fourth Amendment’s warrant requirement, officers may search a vehicle without a warrant when they have probable cause to believe it contains evidence of a crime. The Sixth Circuit cites:

• United States v. Stevenson, 43 F.4th 641 (6th Cir. 2022) – standard of review for suppression rulings (clear error for facts, de novo for law);
• Hernandez v. Boles, 949 F.3d 251, 259 (6th Cir. 2020) – reaffirming that probable cause justifies a warrantless car search.

“Probable cause” is a fluid, commonsense concept. The Supreme Court in Illinois v. Gates, 462 U.S. 213 (1983), described it as a “fair probability” that evidence of a crime will be found at a particular place, and directed courts to consider the “totality of the circumstances.” Maryland v. Pringle, 540 U.S. 366 (2003), likewise applied that flexible standard in the automobile context.

2. Florida v. Harris and K9 Reliability

The central Supreme Court precedent is Florida v. Harris, 568 U.S. 237 (2013). There, the Court held:

• A properly trained and certified narcotics-detection dog’s positive alert typically suffices to establish probable cause to search a vehicle.
• Probable cause analysis remains totality-based: courts assess the dog’s training, certification, and performance, and consider any circumstances that might cast doubt on the particular alert.

Harris rejects rigid rules (such as mathematically requiring a particular field reliability rate) and instead emphasizes a flexible, commonsense approach centered on whether the alert contributes to a fair probability of finding contraband.

3. Probable Cause Is About Probabilities, Not Certainties

The opinion also cites:

• United States v. Martin, 289 F.3d 392, 400 (6th Cir. 2002) – probable cause does not require officers to eliminate all innocent explanations;
• District of Columbia v. Wesby, 583 U.S. 48, 57 (2018) – probable cause “requires only a probability or substantial chance of criminal activity, not an actual showing of such activity” (citation modified).

These cases underscore that the mere possibility that a detected odor might emanate from legal activity (e.g., lawful hemp) rather than illegal activity (e.g., marijuana) does not automatically negate probable cause. The question is whether criminality is reasonably likely, not whether it is certain.

4. Human Smell of Marijuana After Partial Legalization: United States v. Santiago

Crucially, the court relies on its own recent precedent, United States v. Santiago, 139 F.4th 570 (6th Cir. 2025), which held that:

• Even when some forms of cannabis are legal, an officer’s smelling marijuana can still provide probable cause to arrest.

Santiago addressed the argument that legalization of some cannabis products (medical or otherwise) diminished the significance of marijuana odor for probable cause. The court rejected that broad claim, concluding that the smell still contributes to a fair probability of criminal activity unless the surrounding circumstances convincingly show otherwise.

In Saine, the defendant argues that K9 alerts are categorically different from human smell because:

• A dog’s response is “automatic” and not context-sensitive; and
• An officer can cognitively weigh context, such as obvious signs of legal use.

The Sixth Circuit responds by citing Harris to emphasize that context always matters for a K9 alert as well; courts and officers must still consider whether particular circumstances undermine reliability for that specific search.

B. The Court’s Legal Reasoning

1. Reaffirming the Presumption from Harris

The panel begins by restating the key rule from Harris: a K9’s positive alert presumptively supplies probable cause when the government demonstrates that the dog “reliably identifies contraband in controlled settings.” Saine did not challenge the dog’s training or certification; instead he argued that because the dog could not distinguish hemp from illegal marijuana, its alert no longer reliably signaled illegal contraband.

The court rejects this, explaining that:

• Probable cause tolerates uncertainty and risk of innocence.
• A dog’s alert to marijuana odor indicates at least a “substantial chance” that contraband is present, even if some cannabis products are lawful.
• The existence of lawful hemp or marijuana derivatives does not transform the dog's alert into a neutral or meaningless fact; it merely adds an alternative, innocent explanation that need not be excluded to find probable cause.

2. Extending Santiago to K9 Alerts

Saine’s effort to distinguish between human and canine detection is rejected. The court reasons:

• Santiago already held that an officer’s detection of a marijuana odor can provide probable cause despite some forms of legal cannabis.
• There is no convincing basis in this record to treat a dog’s detection differently as a categorical matter.
• As in Harris, the reliability of a particular dog’s alert remains subject to scrutiny based on contextual factors (e.g., handler cues, environmental conditions, over-broad training, etc.).

By explicitly analogizing K9 alerts to human detection under Santiago, the court signals that the mere presence of lawful cannabis products in the legal landscape does not automatically erode the probative value of a marijuana-related alert—whether from a human or a dog.

3. Totality of the Circumstances and the “Hemp is Legal” Argument

Significantly, the court is careful not to say that a K9 alert is always sufficient, no matter the context. Instead, it emphasizes a totality-of-the-circumstances assessment, and expressly acknowledges:

“There may come a day when hemp or other legal cannabis substances are so pervasive that the alert of a K9 trained to identify the smell of marijuana, but not to distinguish between legal and illegal forms of cannabis, no longer tends to indicate a ‘fair probability’ of contraband. … Based on the sparse record before us in this case, that day is not today.”

This passage is doctrinally important. It:

• Leaves open the possibility that, in a future case with a more developed factual record about the ubiquity of legal hemp or cannabis products, a dog’s marijuana alert might carry less weight in the probable cause calculus.
• Confirms that the defense bears a practical burden to develop that record if they wish to challenge K9 alerts on the basis of legal market conditions.

In this case, however, the record was sparse on those issues, and several contextual factors reinforced the inference of criminal activity:

• The known high-crime, drug-related reputation of the motel;
• The BOLO connecting Saine to narcotics trafficking; and
• The K9’s positive alert specifically on Saine’s truck.

Drawing on Pringle and Gates, the court concludes that, in this totality, there was a fair probability that contraband would be found in the truck. Therefore, the officers had probable cause to search it.

C. Complex Concepts Clarified

1. Probable Cause

Probable cause is frequently misunderstood. It is:

• Not proof beyond a reasonable doubt;
• Not a preponderance of the evidence (“more likely than not”);
• A lower, probabilistic threshold—“a probability or substantial chance” of criminal activity, not a guarantee.

Thus, the fact that a K9 may alert to either legal hemp or illegal marijuana does not defeat probable cause. So long as the alert, combined with context, suggests a substantial chance of criminality, the threshold is met.

2. Totality of the Circumstances

Under Gates, courts avoid rigid formulas and instead evaluate all relevant factors:

• The nature of the location (here, a known drug hotspot);
• Background intelligence (the BOLO);
• The dog’s training and certification;
• The presence or absence of exculpatory indicators (e.g., lawful-hemp businesses, medicinal cannabis prescriptions, etc.).

No single factor is determinative; they are weighed together to see if contraband is sufficiently probable.

3. BOLO Alerts

A BOLO (“Be On the Lookout”) is a communication among law enforcement agencies describing a suspect believed to be engaged in specified criminal activity. Though not proof of wrongdoing, a BOLO can meaningfully contribute to probable cause as one part of the total information available to officers.

D. Impact and Critical Assessment

1. Practical Impact on K9 Practices in the Sixth Circuit

Saine solidifies that, within the Sixth Circuit:

• A properly trained and certified drug-detection dog’s alert to marijuana remains a powerful—sometimes decisive—basis for probable cause, despite the legality of hemp and certain cannabis byproducts.
• Officers do not have to conclusively rule out legal cannabis as the source of the odor before searching.

Law enforcement agencies using older K9s that cannot distinguish between lawful hemp and illegal marijuana can, for now, continue to rely on their alerts to justify vehicle searches, so long as there is no strong countervailing evidence that legal uses dominate the context.

2. Defense Strategy Going Forward

Defense counsel seeking to challenge K9-based probable cause in the post-hemp-legalization era will need to:

• Build a factual record: showing, for example, the ubiquity of hemp products in a given jurisdiction, or that a particular area is dominated by legal hemp-related commerce.
• Challenge the specifics of the dog’s training and performance: false positives, alerts to residual odors, responses to legal substances, or handler cueing.
• Highlight contexts where lawful use is especially likely (e.g., near hemp farms, CBD stores, or medical marijuana facilities).

The panel’s caveat about a possible future where hemp is so pervasive that alerts cease to be probative provides a doctrinal foothold for such arguments—but only if adequately supported by evidence in the record.

3. Doctrinal Consistency and Possible Tension

On the one hand, Saine is consistent with longstanding probable cause doctrine and the Sixth Circuit’s own decision in Santiago. It avoids creating a categorical rule that would suddenly invalidate long-used K9 practices simply because some cannabis products have become legal.

On the other hand, critics may argue:

• Treating all marijuana odor as strongly indicative of crime in a regime of partial legalization risks overbreadth and invasive searches of individuals engaged in legal conduct.
• Without empirical scrutiny of how often K9s alert to legal hemp, courts may underestimate the “false positive” problem created by overlapping odors.

Nevertheless, Saine preserves flexibility by insisting that context matters and by expressly acknowledging that the analysis may change as hemp becomes more pervasive and as better empirical data become available.

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III. Evidence Ruling: Text Messages, Rule 404(b), and Knowledge

A. The Rule 404(b) Framework and Cited Precedents

1. Rule 404(b) Basics

Federal Rule of Evidence 404(b)(1) provides:

Evidence of any other crime, wrong, or act is not admissible to prove a person's character in order to show that on a particular occasion the person acted in accordance with the character.

However, Rule 404(b)(2) allows such evidence for other permissible purposes, such as proving:

• Motive,
• Opportunity,
• Intent,
• Preparation,
• Plan,
• Knowledge,
• Identity,
• Absence of mistake or accident, etc.

The Supreme Court in Huddleston v. United States, 485 U.S. 681 (1988), held that before admitting other-acts evidence, the district court need only find there is sufficient evidence for a reasonable jury to conclude that the defendant committed the prior act. This is a preliminary sufficiency, not a full adjudication.

The Sixth Circuit’s standard formulation, cited here from United States v. Clay, 667 F.3d 689 (6th Cir. 2012), requires that:

1. The district court determine there is sufficient evidence to support a jury finding that the defendant committed the other act.
2. The evidence be offered for a proper, non-propensity purpose under Rule 404(b)(2).
3. The evidence’s probative value not be substantially outweighed by unfair prejudice, confusion, or waste of time under Rule 403.

2. Sixth Circuit Gun Cases: Whitlow, Hunter, Gibbs, and Grubbs

The opinion relies on several firearm-related precedents:

• United States v. Whitlow, 134 F.4th 914 (6th Cir. 2025) – upheld admission of photographs of a defendant holding a firearm even though he claimed they depicted a different gun from the one charged. The court treated the question whether the photographs matched the charged gun as a classic factual dispute for the jury.
• United States v. Hunter, 558 F.3d 495 (6th Cir. 2009) – admitted similar gun-related evidence over a Rule 403 objection.
• United States v. Gibbs, 797 F.3d 416 (6th Cir. 2015) – likewise addressed admission of firearm evidence under Rule 403.
• United States v. Grubbs, 506 F.3d 434 (6th Cir. 2007) – the defendant argued here that Grubbs required a stronger nexus between the evidence (a prior description of a gun) and the charged firearm. The Saine court clarifies that Grubbs dealt with the sufficiency of evidence to sustain a conviction, not the admissibility of prior-acts evidence under Rule 404(b).

Additionally, the panel cites United States v. Zipkin, 729 F.2d 384 (6th Cir. 1984), to reiterate the deferential standard for reviewing Rule 403 balancing: on appeal, the court views the evidence in the light most favorable to the proponent, maximizing its probative value and minimizing its prejudicial effect.

B. The Court’s Legal Reasoning on the Text Message

1. Why the Court Says 404(b) Is Not the Right Lens

The core of Saine’s 404(b) argument is:

• The text “I’ve got your gun and stuff in the house” might refer to an uncharged gun.
• If so, it amounts to evidence that Saine previously possessed a different firearm.
• That prior possession could improperly lead the jury to infer a propensity to possess firearms, making him more likely to have possessed the indicted guns.

The panel, however, holds that this mischaracterizes how the district court used the text. The district court admitted it for a non-acts purpose: to show what Saine knew—i.e., that he knew there was a gun at his house and accepted that fact by responding “K.” Knowledge is a mental state, not itself a “crime, wrong, or act.” Therefore:

• The text was not offered as evidence that Saine committed another, distinct “bad act” of unlawful gun possession.
• Instead, it was admitted to show his state of mind regarding the guns charged in the indictment.

Because Rule 404(b) only governs “other crimes, wrongs, or acts,” evidence offered exclusively to prove state of mind—without necessarily positing a separate bad act—is conceptually outside its core scope. In that sense, the opinion narrows the reach of 404(b) by clarifying that not every piece of evidence that hints at “other conduct” is automatically “other-acts” evidence. It depends on what the evidence is being offered to prove.

The district court reinforced this understanding by offering to issue a limiting instruction, telling the jury they could consider the message only for purposes such as knowledge or state of mind—not as evidence of character or propensity. Defense counsel declined that instruction, a strategic decision that likely undermined the force of any appellate argument about propensity misuse.

2. Even If 404(b) Applied, Admission Was Proper

The panel proceeds to say that even if one applied the 404(b) framework, the challenge would fail.

1. Sufficient evidence that the referenced gun is connected to the charged firearms.
   The text was sent only eight days after Tonya bought the Walther and Springfield, and three days before the same guns were found in their shared home—the location Tonya mentioned in her text (“in the house”). While it is theoretically possible the message referred to the unindicted pistol, this ambiguity is for the jury to resolve. As in Whitlow, the court deems competing factual narratives about which firearm is depicted or referenced to be quintessential jury questions. The government’s theory—that “your gun” referred to the Walther and/or Springfield—was sufficiently supported to go to the jury under Huddleston.
2. Proper purpose.
   The government again emphasized a non-propensity purpose: knowledge. Firearm prosecutions often require proof that the defendant knew of, and had some control over, the firearm. A message explicitly stating that a gun at the house is “your gun” strongly supports knowledge and connection to that firearm, which is a legitimate Rule 404(b)(2) purpose if 404(b) applies at all.
3. Rule 403 balancing.
   The court, applying Zipkin, assesses prejudice in the light most favorable to the government. The potential prejudice—namely, that the jury might conclude the text refers to an uncharged gun and infer a general predisposition to have guns—does not “substantially outweigh” the considerable probative value of the message in establishing knowledge and possession of the indicted firearms. Thus, the Rule 403 balancing does not require exclusion.

3. Distinguishing Grubbs

Saine leans on United States v. Grubbs, 506 F.3d 434 (6th Cir. 2007), where the court described as a “tenuous leap” the inference that a defendant possessed a specific gun based on his earlier possession of a “dark-colored” “automatic” gun. In Grubbs, that testimony was inadequate to support conviction without stronger corroboration.

But the panel clarifies:

• Grubbs addressed sufficiency of the evidence—not the admissibility of other-acts or context evidence.
• In Saine, appellate review does not concern whether the evidence alone proved possession; it concerns whether the district court abused its discretion by admitting the texts.

Because Saine did not challenge the overall sufficiency of the evidence, Grubbs is inapposite. The text message, far from being the only evidence of possession, merely formed part of a broader evidentiary picture (including store surveillance and seizure from the shared home).

C. Complex Concepts Clarified

1. Hearsay vs. Non-Hearsay Use

“Hearsay” is an out-of-court statement offered to prove the truth of the matter asserted. Here:

• If the government had offered Tonya’s text—“I’ve got your gun and stuff in the house”—to prove that she in fact had the gun in the house, this would be hearsay.
• But the district court admitted it to show Saine’s state of mind: that he was told about a gun in the house and accepted or acknowledged that information by responding “K.”

When a statement is offered to show its effect on the listener (e.g., to demonstrate notice, knowledge, motive, or state of mind) rather than the truth of the content, it is not hearsay. That is the basis on which the district court (and implicitly the Sixth Circuit) treated the text as non-hearsay.

2. Prior Bad Acts vs. State of Mind Evidence

Rule 404(b) is often over-invoked. A recurring distinction is:

• Evidence that the defendant previously did something wrong (a crime, wrong, or bad act) which might tempt the jury to convict based on character (propensity); versus
• Evidence that shows what the defendant believed, knew, or intended without necessarily alleging prior wrongful conduct.

Here, referring to a gun as “your gun” may suggest prior possession, but that is not the exclusive or necessary inference. The text is directly probative of Saine’s understanding that a firearm at the house was tied to him—supporting knowledge and constructive possession of the currently charged guns. The panel thus treats it primarily as state-of-mind evidence, not as proof of a separate “other bad act.”

3. Limiting Instructions and Strategic Choices

When potentially prejudicial evidence is admitted for a limited, permissible purpose, courts often mitigate risk via a limiting instruction under Rule 105:

• The district court here offered to instruct the jury to consider the text only for Saine’s state of mind or knowledge.
• Defense counsel declined this instruction, a strategic call that can avoid reemphasizing damaging evidence but also removes an appellate argument that the jury misused the evidence.

On appeal, the absence of a limiting instruction cannot be faulted as error where the defense affirmatively declined it; if anything, it underlines the correctness of the district court’s handling of the issue.

D. Impact and Practical Lessons

1. For Prosecutors

Saine underscores that:

• Text messages and similar informal communications with ambiguous references (e.g., “your gun”) can be powerful evidence of knowledge and possession, even if they do not name specific makes and models.
• Prosecutors should clearly articulate at trial the non-propensity purpose (knowledge, state of mind, absence of mistake) for admitting such evidence and, when appropriate, accept or propose limiting instructions to minimize 404(b) challenges.

2. For Defense Counsel

Defense attorneys should:

• Carefully consider whether to accept a limiting instruction; rejecting one enhances the risk that the jury will consider the evidence more broadly, and weakens appellate complaints about propensity misuse.
• Develop factual counter-narratives (e.g., that “your gun” refers to an uncharged, lawfully owned gun; or that the defendant does not claim ownership and the phrase is colloquial).
• Argue, where appropriate, that close nexus requirements (as in Grubbs) matter more for sufficiency of evidence, even if they do not prevent admission.

3. Doctrinal Clarification: Narrowing 404(b)’s Reach

Doctrinally, Saine subtly narrows the automatic reach of Rule 404(b) by:

• Emphasizing that not all evidence with potential “other acts” implications is actually offered as “other acts” evidence.
• Reinforcing that the key question is the purpose for which the evidence is admitted (here, knowledge), not merely its subject matter.

This approach aligns with the inclusive nature of Rule 404(b) (as explained in Huddleston): most relevant evidence is admissible, subject to a proper purpose and Rule 403, and 404(b) is not a catch-all exclusionary device whenever evidence could be construed as suggesting some other wrongdoing.

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IV. Conclusion

United States v. Saine contributes two significant clarifications to Sixth Circuit law.

1. Fourth Amendment / K9 Alerts and Cannabis Legalization.
   The court confirms that a drug-detection dog’s alert to marijuana still presumptively provides probable cause for a vehicle search, even where hemp and some cannabis byproducts are legal and the dog cannot distinguish them. Probable cause hinges on probabilities, not certainties, and legalization alone does not erase the inference of criminality from marijuana odor—especially when reinforced by contextual factors like BOLOs and known drug locations. At the same time, the court leaves open the possibility that the legal and factual landscape could eventually erode the probative force of such alerts in a different case with a more developed record.
2. Evidence / Text Messages, Knowledge, and Rule 404(b).
   The court holds that a text stating “I’ve got your gun and stuff in the house,” used to show the defendant’s knowledge of firearms at his residence, is not “other-acts” propensity evidence in the Rule 404(b) sense. Even if analyzed under 404(b), the message is admissible: the jury could reasonably link “your gun” to the charged firearms, the purpose (proving knowledge) is permissible, and the probative value is not substantially outweighed by any unfair prejudice. Ambiguities about which gun is referenced go to the weight of the evidence, not admissibility.

In the broader legal context, Saine illustrates the judiciary’s attempt to adapt established doctrines—probable cause and Rule 404(b)—to modern developments such as partial cannabis legalization and ubiquitous digital communications. The opinion strikes a balance between protecting constitutional rights and preserving the practical tools law enforcement and prosecutors rely on, while signaling that changing social and market conditions may justify different outcomes in future, better-developed cases.