Police expansion of the stop
After the initial Fourth Amendment seizure or Terry stop, how long can police detain you? The law limits police expansion of the stop beyond its original purpose. A prolonged detention may be illegal. How far can a stop-and-frisk go?
How long can police detain you?
It depends upon all the circumstances. But the most important factor is the original reason for the initial stop.
Let’s consider a traffic stop for speeding. How long do police take to give a speeder a citation and send them on their way? That is the reasonable length of detention after a traffic stop. But anything longer would be an unlawfully prolonged detention.
So, if a police detention is prolonged beyond its reasonable justification under the circumstances, it is illegal. And a judge will suppress evidence found as the result of an illegal expansion of the stop.
Free from Unreasonable Searches & Seizures
The United States and Minnesota Constitutions guarantee the individual’s natural right to be free from unreasonable searches and seizures. U.S. Const. amend. IV; Minn. Const. art. I, 10.

The Minnesota Supreme Court held that Article I, section 10, of the Minnesota Constitution, requires application of Terry v. Ohio, 392 U.S. 1 (1968), when evaluating the reasonableness of seizures during traffic stops for a minor law violation. State v. Askerooth, 681 N.W.2d 353, 363 (Minn. 2004).
The United States Constitution guarantees:
“[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated …”
U.S. Constitution Amendment IV.
A Fourth Amendment seizure
A traffic stop or investigatory detention is an intrusion upon your liberty. And it’s a “seizure” within the meaning of the Fourth Amendment. An investigatory detention is a “brief” seizure by police based on a “reasonable suspicion of criminal activity.” And it’s a narrow exception to the probable cause requirement of the Fourth Amendment. Terry v. Ohio, 392 U.S. 1, 26-27 (1968).
Even so, the police officer must have a “reasonable, articulable suspicion of criminal activity” or observe a violation of law, before imposing even a brief, investigatory detention.
So what is “a reasonable, articulable suspicion?” The police officer must have had specific, articulable facts, reasonably suggesting that criminal activity has occurred or is imminent.
This is an objective standard, not a subjective one. The word “reasonable” means it’s an objective standard. A sincere, good faith mistake is not good enough. A police officer’s subjective belief is not enough for a stop and frisk, or a prolonged detention.
After the stop or seizure
After a police officer stops a vehicle, she “may ask the detainee questions in order to dispel or confirm his suspicions, but questioning is limited in scope to the circumstances that justified the stop.” United States v. McGauley, 786 F.2d 888, 890-91 (8th Cir. 1986). The U.S. Supreme Court said:
“The stop and inquiry must be reasonably related in scope to the justification for their initiation. Typically, this means that the officer may ask the detained a moderate number of questions to determine his identity and to try to obtain information confirming or dispelling the officer’s suspicions”
Berkemer v. McCarty, 468 U.S. 420, 439-40 (1984)
During an investigatory detention, a police officer must use the least intrusive means of detection reasonably necessary to address the officer’s reasonable suspicion. US v. Gill, 513 F. 3d 836, 845 (8th Circuit 2008). And this includes any police stop-and-frisk.
Expansion of the stop’s scope & length
Limited scope: The scope of a stop is “strictly tied to and justified by the circumstances” for the initial stop:
“In essence, Article I, Section 10 of the Minnesota Constitution requires that each incremental intrusion during a traffic stop be tied to and justified by one of the following:
State v. Askerooth, 681 N.W.2d 353, 364 (Minn. 2004)
(1) the original legitimate purpose of the stop,
(2) independent probable cause, or
(3) reasonableness, as defined in Terry.
Furthermore, the basis for the intrusion must be individualized to the person toward whom the intrusion is directed.”
Expansion of the stop: If a stop is initially justified on one basis, a police officer cannot expand the scope or length of the police investigation without additional, reasonable suspicion to support the expansion. And a police officer may expand the scope of the stop only if the officer has reasonable, articulable suspicion that the person is engaged in criminal activity.
So, to expand the scope of the stop, “the officer must have a particularized and objective basis for suspecting the particular person stopped of criminal activity.” United States v. Cortez, 449 U.S. 411, 417-18 (1981). And this applies to a prolonged detention as well as a stop-and-frisk.

Length of investigatory detention
“An investigative detention must be temporary and last no longer than is necessary to effectuate the purpose of the stop.” State v. Wiegand, 645 N.W.2d 125, 135 (Minn. 2002).
So police may continue to detain a person only “as long as the reasonable suspicion for the detention remains.” State v. Moffatt, 450 N.W.2d 116, 119 (Minn. 1990)
The United States Supreme Court formula for evaluation of the length of detention:
“In assessing whether a detention is too long in duration to be justified as an investigative stop, we consider it appropriate to examine whether the police diligently pursued a means of investigation that was likely to confirm or dispel their suspicions quickly, during which time it was necessary to detain the defendant.”
United States v. Sharpe, 470 U.S. 675 (1985).
If there was no objective reason to expand or prolong the initial Fourth Amendment seizure, subsequent investigative questioning, requests for consent to search, or searches are illegal. Therefore, resulting evidence must be suppressed. See, State v. Fort, 660 N.W.2d 415, 419 (Minn. 2003).
Dog sniff: An unlawful expansion of the stop and prolonged detention can also lead to a dog-sniff search. But this results in suppression of illegal evidence. See, State v. Miller, 659 N.W.2d 275, 280 (Minn. Ct. App. 2003).
Best practices at a traffic stop
What does all this mean? And how can you use this information? We can make practical use of it both prospectively and retrospectively. It can both avoid future problems and help solve problems from the past. For more practical tips, see our:
- How to Assert Your Rights: Protect Yourself from Police
- Countermeasures at a DWI Stop
- How to Avoid a Marijuana Arrest in a Car: Nine Tips
Looking ahead: expansion of the stop
After a police stop, in a car or otherwise, how can this law guide best behavior?
It’s best to maintain a professional, courteous demeanor while interacting with police during a stop; while at the same time faithfully asserting your rights.
How? Don’t lie, and don’t volunteer information that a prosecutor could be use against you – both. After all, you may not understand what information prosecutors can cherry-pick to use against you until after it’s too late to take it back.
So, when in doubt remember: silence is golden.
If you sense a police officer may detaining you longer than necessary during a stop and frisk – ask the officer: “am I free to leave?” Or “am I being detained?” Or “may I go now?”
Why ask that question? Because the police officer will then have to stop a moment and evaluate. Can she justify, at that moment, articulable, reasonable suspicion sufficient to expand the scope of the stop or prolong the length of the detention?
This forces a logical choice. Is the police officer invoking the power of the State, imposing a Fourth Amendment seizure (or “stop”)? If so, then leaving would a crime, Fleeing Police. But if not, then the police office must concede that they are not doing so, and that you are “free to leave.”
If the police officer is not invoking a “stop” or is terminating it due to lack of justification; the officer will then let you go, with or without your ticket. That would be your cue to leave in an orderly way. (“Free to go” means leave now.)

Solving the Problem from the Past
But if the police officer continues the detention, the police officer may later be forced to justify it in court.
And if the police officer cannot articulate facts known at the time that justify the stop and frisk, prolonged detention or expansion of the stop, the judge will suppress the evidence.
If police obtained evidence after an illegal expansion of the original stop or unlawfully prolonged the length of the investigatory detention, your defense lawyer can ask a judge to suppress that evidence.
And lacking other evidence, the judge will then dismiss the criminal charges.
Two common fact patterns: expansion of the stop
Defense Attorney Thomas Gallagher sees two common fact patterns for expanded stops and prolonged detention – dog-sniff searches and consent searches.
Dog-sniff Search: expansion of the stop
A police officer may stop a vehicle and want to conduct a dog-sniff search, for example for illegal drugs.
But unless she has a dog in the car, it may take a long time to get one there.
So, if there is no objective basis for prolonging the detention, any subsequent search, including a dog-sniff search, is illegal. And a judge will suppress evidence resulting from the illegal expansion of the stop. (“Waiting for a dog” is not a reasonable basis to suspect a crime.)
See our article: Odor of Marijuana: Probable Cause?
Consent search & police coercion
Another common ploy is to prolong an investigatory detention beyond its original purpose. The prolonged detention, without any objective reason for doing so, will delay and stress the person stopped. The police officer’s clear but unspoken message is “give ‘consent’ or be detained indefinitely or worse.” This is a technique to coerce the person into “consenting” to a search.
The police officer suggests a quid pro quo: “I’m going to detain you indefinitely, until you relent and consent to a search.” But that is not reasonable suspicion of a crime, so illegal.
Attorney Gallagher sees many variations of police coercion to get “consent.” But, the product of coercion is not consent, is it?
Did a person who “consented” to sex under coercion, really consent? Or was it rape? So, when police coerce people into “consenting,” that is not consent. And Judges should not let police get away with that or reward them for it.
Examples? A police officer detains you longer than necessary for a speeding ticket. And then she asks you to “consent” to a search. But when you don’t, she says she’ll have to detain you until the drug dog gets there.
The prolonged detention is coercive. You’ll be free to leave if you “consent” to a search. Otherwise, you’ll be stuck there for who knows how long.
Police officers can be creative. They come up with many, varied ways of pressuring and coercing people. Repetition is a common tactic, like a four-year-old.
But don’t you cave. Hang tough. And assert your rights. You don’t need to justify your rights. After all, they’re yours. Be polite if you can manage it. But assert your rights. So don’t “consent.” And don’t answer questions without consulting a defense lawyer.
“Many citizens because of their respect for what only appears to be a law are cunningly coerced into waiving their rights due to ignorance.”
JUSTICE FRANKFURTER, U.S. v. Minker, 350 U.S. 179 (1956)
Never consent to a search
Prevention works better than cure. But if you already did, a defense lawyer like Thomas Gallagher can make a motion to suppress evidence obtained in an illegal search based on coerced “consent.”
The Defense Attorney’s role
Your defense attorney should collect available facts. And then he should identify potential criminal defenses, including illegal expansion of the stop, prolonged detention, and illegal stop and frisk.
If facts support it, he’ll prepare a motion to suppress illegal evidence as a result. Then the judge will preside over a Contested Omnibus Hearing to decide the facts, and eventually apply the law. And the judge can then suppress illegal evidence.

Thomas Gallagher is an experienced criminal attorney who has won many cases as a result of these issues.
Attorney Gallagher also teaches police, other lawyers and judges the law of search and seizure.
He can provide you with the best defense in your criminal case.
Question? Call Lawyer Thomas Gallagher: 612 333-1500
Other articles of interest
Avoiding Traffic Stops – Minnesota Laws
Illegal Stop by Police
Criminal Evidence Law | Suppressing Illegal Evidence