Police cannot stop a vehicle merely because it leaves a house or property associated with suspected drug activity. A vehicle stop is a Fourth Amendment seizure, and officers ordinarily need particularized reasonable suspicion directed at the vehicle, driver, or occupants.
If police stopped your vehicle because you visited or left a location under investigation, contact federal criminal defense attorney Michael J. Petro to discuss whether the stop and resulting evidence can be challenged.
A Vehicle Stop Requires Legal Justification
Police may stop a vehicle when they have reasonable suspicion that the driver committed a traffic violation or that the vehicle’s occupants are involved in criminal activity.
Reasonable suspicion must be based on specific and articulable facts. It requires more than:
• A hunch.
• General suspicion about a neighborhood.
• Association with a suspected person.
• Presence at a location under investigation.
• Departure from property where police believe crimes have occurred.
• Innocent travel behavior described as suspicious.
The court must examine the facts known to officers when the stop began. Evidence discovered afterward cannot retroactively justify an unlawful seizure.
Suspicion About a Place Does Not Automatically Transfer to a Person
Police may have substantial evidence that drugs are stored, manufactured, or sold at a particular location. That suspicion does not automatically establish that every visitor is participating in the suspected crime.
A person may visit a home or business for countless innocent reasons. The Fourth Amendment generally requires individualized suspicion rather than guilt by association.
Courts should distinguish between:
• Evidence connecting criminal activity to a location.
• Evidence connecting the particular vehicle or person to that activity.
Without the second connection, stopping every person who enters or leaves the property would give officers nearly unlimited discretion.
What Additional Facts May Support a Stop?
Police may consider a person’s connection to suspected property as one part of the totality of the circumstances. Additional facts may sometimes establish reasonable suspicion.
Those facts may include:
• A reliable informant specifically identifying the vehicle or occupant.
• Surveillance showing conduct consistent with a drug transaction.
• A very brief visit combined with other evidence of drug sales.
• Objects transferred between a person and a known suspect.
• A match to a detailed description connected to a recent crime.
• Evasive driving after the vehicle’s occupants notice police.
• An independently observed traffic violation.
• Reliable evidence that the person is transporting contraband.
The government should explain why the observed conduct supports a particularized suspicion, rather than merely describing innocent activity in suspicious terms.
United States v. Bohman
In United States v. Bohman, No. 10-3656, an informant told a police sergeant that methamphetamine had been manufactured several times at a hunting cabin located on a rural property.
The informant provided several details. He reportedly identified:
• The property where the cabin was located.
• An anhydrous ammonia tank recently seen at the cabin.
• A locked cable blocking the driveway.
• A green Mercury Grand Marquis driven by a suspected methamphetamine manufacturer.
The officer drove to the property at approximately 11 p.m. As he arrived, a vehicle emerged from the driveway.
The officer immediately activated his emergency lights, positioned his police vehicle in front of the approaching car, and stopped it.
The officer admitted that he had not observed a traffic violation before initiating the stop.
Police Stopped the Wrong Vehicle
The informant had identified a green Mercury Grand Marquis. The vehicle stopped by police was a maroon Chevrolet Beretta.
The officer stopped the Beretta because it was the first vehicle leaving the suspected property. Before the seizure, police had no particularized information identifying that vehicle or its occupants as participants in criminal activity.
Only after stopping the car did the officer identify Daniel Bohman as the driver and Jake Barttelt as the passenger. The officer then reported smelling anhydrous ammonia and obtained incriminating information.
The government attempted to rely on these later discoveries to defend the investigation. But the constitutional question concerned what police knew before the officer activated his lights and blocked the Beretta.
Why the Seventh Circuit Reversed
The Seventh Circuit held that generalized suspicion concerning the property did not provide reasonable suspicion to stop the first vehicle that emerged from it.
The informant had described a different vehicle. Police did not observe a traffic violation, dangerous driving, an exchange, or other conduct independently connecting the Beretta to criminal activity before the stop.
The court explained that suspicion of illegal activity at a particular place does not automatically transfer to everyone who leaves that place.
Because the stop lacked individualized reasonable suspicion, the Seventh Circuit reversed the order denying Bohman’s motion to suppress and remanded the case for further proceedings.
Later Evidence Cannot Justify an Earlier Stop
The government may emphasize what officers discovered after stopping a vehicle. That evidence may include:
• The odor of drugs or chemicals.
• Contraband in plain view.
• Nervous behavior.
• Inconsistent answers.
• Incriminating statements.
• A police dog alert.
• Evidence recovered during a later search.
These facts may become relevant after a lawful stop, but they cannot supply the missing justification for the original seizure.
The court must freeze the sequence at the moment police restrained the vehicle and ask whether the facts then known established reasonable suspicion.
A Traffic Violation Can Independently Justify the Stop
The rule is different when an officer observes an actual traffic violation.
Under Whren v. United States, an objectively valid traffic violation may justify a stop even when the officer’s subjective purpose is to investigate drugs.
Defense counsel should examine whether:
• The alleged traffic violation actually occurred.
• The officer could see the violation from the claimed position.
• Dashboard or body camera video supports the officer.
• The traffic law applies to the alleged conduct.
• The officer made an objectively reasonable interpretation of the law.
• The violation was identified before rather than after the stop.
Police cannot invent a traffic violation after discovering evidence.
Informant Information Must Be Reliable and Particularized
Information from an informant may support a vehicle stop, but courts must examine its reliability and connection to the person actually detained.
Relevant considerations include:
• Whether the informant was known or anonymous.
• Whether the informant had provided reliable information previously.
• Whether the informant personally observed the reported conduct.
• How recently the informant obtained the information.
• Whether the informant identified a specific vehicle or person.
• Whether police corroborated important details.
• Whether the information predicted future conduct.
In Bohman, the informant identified a particular vehicle, but police stopped a different one. Corroborating the location did not establish that every vehicle leaving the property was involved in methamphetamine production.
Collective Knowledge Must Exist Before the Stop
A stop may sometimes be supported by information known collectively to officers working together.
For example, one officer may direct another officer to stop a vehicle based on information developed during an investigation. The stopping officer does not always need personal knowledge of every fact.
But the government must establish that the necessary information existed before the stop and was properly connected to the law enforcement team’s decision.
Collective knowledge cannot be assembled after the fact from unrelated observations that no officer used to initiate the seizure.
Does a Search Warrant Authorize Detention?
In Michigan v. Summers, the Supreme Court recognized limited authority to detain occupants at premises while officers execute a valid search warrant.
That authority is not unlimited.
In Bailey v. United States, the Supreme Court held that the categorical authority associated with a premises warrant extends only to occupants in the immediate vicinity of the property being searched.
When police follow and stop someone after that person has left the immediate vicinity, officers generally need an independent constitutional justification for the detention.
Relevant considerations may include:
• The person’s distance from the premises.
• Whether the person remained within sight of the property.
• Whether the person was still within an area normally associated with the premises.
• Whether reentry was realistically possible.
• Whether independent reasonable suspicion or probable cause existed.
A warrant to search a house does not become a general license to stop everyone who previously visited it.
Length and Scope of the Stop
Even when the initial vehicle stop is valid, police must not extend it beyond the time reasonably necessary to address its purpose unless additional reasonable suspicion develops.
Officers may not delay traffic-related tasks merely to investigate unrelated drug activity or wait for a police dog.
Defense counsel should create a precise timeline showing:
• When the vehicle was seized.
• When the officer approached.
• When documents were requested.
• When records checks began and ended.
• When a citation or warning could have been completed.
• When additional questioning occurred.
• When a police dog was requested and arrived.
• What new facts allegedly justified prolonging the detention.
A valid beginning does not excuse an unlawful extension.
Evidence Derived From an Unlawful Stop
When police obtain evidence through an unconstitutional vehicle stop, the defense may seek suppression of both the evidence discovered immediately and later evidence derived from the stop.
Potential derivative evidence may include:
• Physical evidence found in the vehicle.
• Statements by the driver or passengers.
• Consent obtained during the detention.
• Evidence found during a later premises search.
• Information used to obtain a search warrant.
• Evidence recovered after an arrest resulting from the stop.
The government may argue that an exception applies, such as the independent source, inevitable discovery, or attenuation exceptions. Each claim requires evidence and a fact-specific analysis.
Challenging the Vehicle Stop
A motion to suppress should identify the exact facts available to the officer before the officer initiated the seizure.
Important evidence may include:
• Body camera and dashboard camera recordings.
• Dispatch communications.
• Informant reports and recordings.
• Surveillance logs.
• Search warrant affidavits.
• Vehicle descriptions.
• License plate information.
• Officer reports.
• Location and timing data.
• Testimony about when officers learned each fact.
The government should not be permitted to combine generalized suspicion about a property with evidence discovered after the stop and call the result reasonable suspicion.
Michael J. Petro represents clients facing federal criminal charges in Tampa and Chicago. If police stopped your vehicle merely because it left a location associated with suspected drug activity, contact federal criminal defense attorney Michael J. Petro.