When a Friend's Hunch Is Not Enough: The Supreme Court of Maryland Redraws the Line on Terry Stops in Kopp v. State by Alex Chanthunya, LL.M (AU)

A late January evening in a Germantown, Maryland townhouse community. A black sedan parked near a dead end. A police sergeant receives a call on his personal cell phone from a woman he has known for more than two decades. She tells him the car is unfamiliar, that it has been there a while, that people inside are using cell phones. She thinks, she says, the occupants might be breaking into vehicles.

That tip, unrecorded, uncorroborated in any constitutionally meaningful sense, resting entirely on one woman's neighborhood unease, was enough for three police cruisers to converge on the scene, block the car's exit, and illuminate it with overhead spotlights. The arrest that followed, and the firearm and narcotics recovered, came to turn entirely on one question: Did that tip provide reasonable suspicion to stop Xavier Kopp's vehicle?

On May 26, 2026, the Supreme Court of Maryland answered that question with a firm no. Kopp v. State, No. 34, September Term, 2025. The opinion, written by Justice Watts with Justice Gould concurring, reversed the Appellate Court of Maryland and suppressed the evidence. The decision is significant not because it announces a new rule, it does not, but because of what it exposes about how Fourth Amendment doctrine is misapplied in practice, sometimes by officers, sometimes by trial courts, and sometimes by the lawyers who litigate suppression hearings without adequate preparation.

What follows is an analysis of the doctrine the Court applied and the lessons that any serious criminal practitioner should extract from it.

The Foundation: What Terry Actually Requires

Terry v. Ohio, 392 U.S. 1 (1968), authorizes a brief investigatory detention, a stop when an officer has a reasonable, articulable suspicion that criminal activity may be afoot. The standard is less demanding than probable cause. That much is well-settled. What tends to get lost is that "less demanding" does not mean "undemanding." The officer must be able to articulate specific, objective facts that, viewed in light of the totality of the circumstances, give rise to a particularized basis for suspecting legal wrongdoing. United States v. Arvizu, 534 U.S. 266, 273 (2002). A hunch is not enough. An officer's inchoate suspicion, as the Court in Terry itself put it, is not enough. 392 U.S. at 27.

These are not rhetorical formulations. They are constitutional requirements with real consequences, as Kopp makes clear.

The Tip That Was Not a Tip

The caller in Kopp was known to the sergeant personally, known for over twenty years, described at the suppression hearing as a "credible individual." The State placed considerable weight on that relationship. The Appellate Court of Maryland credited it. The Supreme Court of Maryland was unmoved.

The reason lies in a distinction that practitioners regularly blur: credibility and reliability are not the same thing. Credibility is about whether a person is honest. Reliability, in the Fourth Amendment sense, is about whether the information they are providing has an adequate basis to be trusted as accurate. A deeply credible person can convey information that is unreliable. The most honest neighbor in the subdivision can observe a parked car with people in it using cell phones and draw from those innocuous facts a conclusion that is sheer speculation. Her honesty does not transform her speculation into reliable intelligence.

The Supreme Court in Illinois v. Gates, 462 U.S. 213 (1983), established that the relevant factors when evaluating an informant's tip under the totality of the circumstances are the tipster's veracity, reliability, and, critically, basis of knowledge. Alabama v. White, 496 U.S. 325, 328–29 (1990), refined this further, holding that a tip must exhibit sufficient "indicia of reliability" to justify an investigative stop. What courts look for is whether the content of the tip demonstrates that the tipster had actual knowledge about criminal activity, not merely a proximity to it, and not merely an opinion about it.

The caller in Kopp observed a parked car. She did not observe anyone breaking into a vehicle. She did not observe a weapon, drugs, or any conduct that is inherently criminal. She observed an unfamiliar car with people in it, in a residential neighborhood, at night. From that, she formed a belief, or perhaps a fear, that something might be wrong. Her basis of knowledge was contemporaneous observation of entirely innocent conduct. The tip therefore lacked any "indication of the caller's basis of knowledge for the prediction that the occupants of the car may have been breaking into cars." Kopp, slip op. at 20.

That absence is fatal. The Court in Florida v. J.L., 529 U.S. 266, 271 (2000), was explicit that a tip must provide more than a way to locate a particular person; it must be "reliable in its assertion of illegality, not just in its tendency to identify a determinate person." Id. at 272. Confirming that a black sedan was parked where the caller said it was parked confirms nothing about whether the occupants were committing a crime.

Corroboration That Corroborated Nothing

Sergeant Muollo arrived at Rosebay Court, found a black sedan matching the caller's description, observed that there were people in the vehicle, and concluded that he had corroborated the tip. The circuit court agreed. The Appellate Court of Maryland agreed. The Supreme Court of Maryland did not.

The lesson here is one of the most practically important in the entire opinion: corroboration of an informant's description of a subject's observable characteristics does not corroborate the informant's allegation of criminal activity.

This principle emerges directly from J.L. In that case, an anonymous tip that a young Black man at a bus stop wearing a plaid shirt was carrying a gun was followed by officers who found precisely such a person in precisely that location. The Supreme Court of the United States still concluded there was no reasonable suspicion. The officers had corroborated only the tipster's ability to describe what they could observe themselves. That corroboration "does not show that the tipster has knowledge of concealed criminal activity." J.L., 529 U.S. at 272.

What would sufficient corroboration look like? The contrast case is instructive. In Alabama v. White, 496 U.S. 325 (1990), officers received a tip with predictive content, a specific woman would leave a specific apartment at a specific time in a specific car, drive a specific route to a specific motel, and carry cocaine. When officers observed the woman do exactly what the tipster predicted, the corroboration was meaningful because it validated the caller's "inside information." Id. at 332. Predicting future behavior that only an insider could know is qualitatively different from describing something that is plainly visible to anyone standing on the street.

In State v. Rucker, 374 Md. 199, 821 A.2d 439 (2003), the Maryland courts found sufficient reliability in a tip from a confidential informant who not only provided detailed physical and vehicular descriptions but also predicted when and where the subject would appear. The source's accuracy on predictive details, combined with a track record of providing reliable information, rendered the tip constitutionally adequate. Id. at 213–15, 821 A.2d at 447–49.

The caller in Kopp predicted nothing. She described a static situation that any passerby could observe. Sergeant Muollo's arrival and confirmation that the static situation existed told him nothing about whether what the caller feared was true.

The High-Crime Area Problem: Geography Is Not a Substitute for Evidence

One of the most practically significant passages in Kopp concerns the "high-crime area" designation, a factor that has become, in practice, something of a jurisprudential wild card. Officers routinely invoke it, trial courts routinely credit it, and appellate courts far too rarely scrutinize it.

The Supreme Court of Maryland had already addressed this directly in Washington v. State, 482 Md. 395, 287 A.3d 301 (2022), where it laid out with precision what is required to establish that a location qualifies as a high-crime area for purposes of the Terry analysis. Testimony must be particularized to the specific location or geographic area at issue, not a broad police district, not a multi-mile beat. It must identify the specific criminal activity known to occur there, the temporal proximity of that activity to the time of the stop, and the conduct giving rise to the officer's suspicions must be consistent with the crimes alleged to make the area high-crime. Id. at 443, 287 A.3d at 330.

The testimony in Kopp failed these requirements comprehensively. Sergeant Muollo testified about crime in the "Nancy-1 beat" a geographic area the defense established was approximately three to four miles long and up to two miles wide, encompassing multiple neighborhoods. The calls-for-service data he cited was beat-wide. He had not examined that data to determine which calls occurred nearest to Rosebay Court. He had not reviewed it before the stop at all, it was obtained from a crime analyst after the arrest and presented at the suppression hearing. The 400 calls for service in 2022 that he referenced were not geographically analyzed.

Defense counsel, in one of the more creative witness choices seen in a Maryland suppression hearing, called one of Mr. Kopp's own attorneys as a fact witness. That attorney had used Google Maps to plot the January 2023 calls for service against the location of 13 Rosebay Court. His testimony: the closest call that month was 0.6 miles away, an anomaly, while all others were at least 1.3 miles distant. In the thirteen-month period covering 2022 through January 2023, there was one call for service among the twelve streets closest to 13 Rosebay Court. That call, in July 2022, was for a larceny under fifty dollars.

That is not a high-crime area. Not under any standard. The circuit court avoided this problem by effectively sidestepping the Washington framework and instead vaguely noting "a significant level of crime in the area." Kopp, slip op. at 9. The Supreme Court of Maryland was direct about why that approach is constitutionally impermissible: allowing a trial court to find some generalized elevated crime level without applying the Washington requirements would "enable trial courts to circumvent the high-crime area analysis." Id. at 32. That kind of evasion cannot stand.

The temporal dimension of the crime-data problem cuts deeper still. Reasonable suspicion must be based on facts "known to the officer at the time of the stop." Terry, 392 U.S. at 21. Information assembled after the arrest to justify the stop after the fact is not information the officer possessed when the detention occurred. Sgt. Muollo testified that he reached out to the district crime analyst, after the arrest, to get "specific stats" to "back up" his understanding that the area was high-crime. The Supreme Court recognized this for what it is: post-hoc rationalization, not contemporaneous reasonable suspicion.

Movement That Was Not Flight

The State also argued that Mr. Kopp's vehicle moving slowly forward when police approached constituted flight, elevating the analysis. Sergeant Muollo testified that the car moved at "5 to 10 miles per hour" and that he believed the driver was attempting a three-point turn. The Court disposed of this argument briefly, but the analysis is worth unpacking because "flight" in the Terry context has a specific meaning that courts and litigants frequently misapply.

In Washington v. State, the defendant fled headlong from officers who were at a distance, jumped fences, and attempted to conceal himself behind a bush. That is flight in the constitutional sense, reckless, unprovoked, deliberately evasive. The Court in Washington was careful to define the term: "headlong flight is reckless, without deliberation or delay, flight lacking in calmness or restraint." 482 Md. at 449–50, 287 A.3d at 334. Flight means active evasion, not movement.

The Supreme Court in Illinois v. Wardlow, 528 U.S. 119 (2000), while endorsing unprovoked headlong flight in a high-crime area as a factor supporting reasonable suspicion, simultaneously reaffirmed that "[a]ny 'refusal to cooperate, without more, does not furnish the minimal level of objective justification needed for a detention or seizure.'" Id. at 125 (quoting Florida v. Bostick, 501 U.S. 429, 437 (1991)). A person has every right to ignore police, to move their car when approached, to go about their business.

What Sgt. Muollo observed was a car beginning to move, slowly, at night, on a dead-end street, when police arrived. The officer himself testified he thought the driver was making a three-point turn. That assessment, the contemporaneous assessment, is telling. A three-point turn is not flight. The Supreme Court of Maryland concluded accordingly: "movement of car did not constitute flight and was circumstance that added nothing to reasonable suspicion analysis." Kopp, slip op. at 2.

The Personal Cell Phone Call and What It Tells Us

There is a detail in Kopp that does not receive headline treatment but deserves sustained attention from practitioners: this call was not made to 911, not to a police non-emergency line, not through any official channel. The caller dialed Sergeant Muollo's personal cell phone directly.

Courts have recognized, including in Trott v. State, 473 Md. 245, 249 A.3d 833 (2021), that tips made through 911 emergency systems carry heightened indicia of reliability because those calls are recorded, the caller's location can be identified, and the system's accountability deters false reports. Id. at 267, 249 A.3d at 846. A caller who uses 911 assumes legal accountability for a false report and cannot easily conceal their identity.

None of those accountability mechanisms applied here. The call was unrecorded. No notes were taken. The caller wanted to remain anonymous. Even the police report's quotations of what she said were described by Sergeant Muollo as not verbatim. By the time of the suppression hearing, the precise content of the call was irrecoverable known only through the recollection of an officer who had an interest in the outcome.

The Supreme Court treated this circumstance as relevant to the overall reliability calculus. It cannot be used as a "call for service" to import reliability benefits that official call-for-service systems provide. The court's analysis on this point is a quiet warning to prosecutors and officers who seek to dress up unofficial communications as something more formal than they are.

Totality of the Circumstances Does Not Mean Aggregation of Insufficiencies

Perhaps the most enduring analytical contribution of Kopp lies in what the Court did with the totality-of-the-circumstances test. Defense lawyers regularly confront the following argument at suppression hearings: yes, each factor alone may be innocent, but when you add them all together, the tip, the area, the car's movement, the time of night, the out-of-state tags , the sum exceeds reasonable suspicion. Trial courts are often receptive to this argument. It has a facially commonsense quality. Kopp is a careful illustration of why the argument fails when every factor in the supposed sum is itself legally deficient.

The court did not dispute that multiple factors can together establish reasonable suspicion even when each is innocuous in isolation. That proposition has solid support: United States v. Sokolow, 490 U.S. 1 (1989); Arvizu, 534 U.S. at 277–78. The point, rather, is that adding together a tip that establishes no criminal nexus, corroboration that confirms only observable physical facts, crime area testimony based on data not known at the time of the stop and not particularized to the location, and vehicle movement the officer himself attributed to a three-point turn produces a sum that is still constitutionally insufficient. Garbage in, garbage out. The totality-of-the-circumstances test is not a laundering mechanism.

What the analysis in Kopp demonstrates is that courts must treat each factor not merely as a datum to be weighted but as a question about what that factor actually establishes. A tip does not become more reliable because a high-crime area designation accompanies it, particularly when that designation is itself unproven. An unproven high-crime area does not make slow vehicular movement look more like flight. Insufficiency compounds. It does not transform.

What Defense Counsel Got Right

The suppression hearing in Kopp is a model worth examining on its own terms.

Defense counsel challenged the high-crime area testimony directly and specifically, which many practitioners fail to do. Rather than offering vague counter-argument, the defense team did the analytical work, using publicly available calls-for-service data and Google Maps to map the spatial distribution of crime relative to the stop location. That analysis revealed what the officer's beat-wide characterization concealed: the immediate neighborhood surrounding 13 Rosebay Court was, by any reasonable measure, not a high-crime area.

More unusually, defense counsel called one of Mr. Kopp's own attorneys as a witness to present that analysis. It is a rare maneuver, and it was strategically sound here because it introduced specific, quantifiable data into a hearing that the prosecution was trying to win on generalities.

Defense counsel also objected, during the suppression hearing, to the State's use of the word "community" when questioning the officer, specifically on grounds that the term was geographically overbroad under Maryland case law. That is precisely the kind of objection that forces the record to reflect whether the officer's testimony actually satisfies the Washington standard. Without that objection, a vague answer is a vague answer and vague answers about "community" crime levels have a way of becoming findings that an area is high-crime.

The practical lesson is straightforward: the high-crime area element should never be conceded at a suppression hearing without demanding that the officer articulate, on the record, the specific geographic boundaries of the claimed area, the specific criminal activity known to occur there, when that activity occurred, and how it relates to the location of the stop. Generic testimony about a police beat or district is not enough. Washington says so. Kopp confirms it.

A Note on What the Case Does Not Decide

Kopp does not hold that tips from known sources are constitutionally worthless. It does not hold that police may never conduct a Terry stop based on a personal acquaintance's tip. What it holds is that familiarity with the caller, without more, does not substitute for the quality of the information the caller provides.

There remains a meaningful distinction between a known informant with a track record of providing accurate information about criminal activity, the kind of informant at issue in Rucker, and a neighbor who calls an officer she has known personally because she is suspicious of a parked car. The former carries reliability rooted in demonstrated accuracy. The latter carries credibility rooted in personal relationship. These are different things, and courts must treat them as such.

The distinction between the tip in Kopp and a constitutionally adequate tip from a known source is not formalistic. It is functional. Reliability in the Fourth Amendment context means that the information, considered objectively, gives an officer a particularized basis for suspecting criminal activity. The question is not whether the officer trusted his source. The question is whether the information the source provided,  evaluated against the Gates factors and the standard established in White was of the type and quality that, when corroborated, furnishes reasonable suspicion. The Kopp tip was not.

Conclusion

Kopp v. State is a reminder that the Fourth Amendment does not yield to familiarity, generalized neighborhood unease, or after-the-fact statistical assembly. It requires that an officer possess, before the moment of detention, a particularized and objective basis for suspecting wrongdoing, not a community's ambient fear of crime, not an acquaintance's hunch, not data pulled together after the arrest to explain an impression formed before it.

For defense practitioners, the case is a checklist in disguise: examine the tip's content, not just its source; demand specificity when the State invokes high-crime area; distinguish corroboration of identity from corroboration of illegality; and probe the temporal relationship between everything the officer claims to have known and when he actually knew it.

For the prosecution, the case is a disciplinary notice. Officers must understand the difference between suspicion and reasonable suspicion before they activate their emergency lights. Suppression hearings must be prepared with the same rigor as the underlying investigation. The framework established in Washington is not a procedural obstacle — it is a constitutional floor. And as Kopp makes unmistakably clear, that floor will hold.

Cases cited

Kopp v. State of Maryland, No. 34, September Term, 2025 (Md. May 26, 2026); Washington v. State, 482 Md. 395, 287 A.3d 301 (2022); Terry v. Ohio, 392 U.S. 1 (1968); Alabama v. White, 496 U.S. 325 (1990); Illinois v. Gates, 462 U.S. 213 (1983); Florida v. J.L., 529 U.S. 266 (2000); State v. Rucker, 374 Md. 199, 821 A.2d 439 (2003); Trott v. State, 473 Md. 245, 249 A.3d 833 (2021); Illinois v. Wardlow, 528 U.S. 119 (2000); United States v. Arvizu, 534 U.S. 266 (2002); Florida v. Bostick, 501 U.S. 429 (1991); United States v. Sokolow, 490 U.S. 1 (1989).