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Commonwealth v. Almonor

482 Mass. 35, 120 N.E.3d 1183 (2019)

The Massachusetts decision holding that police conduct a search when they cause a suspect's cell phone to reveal its real-time GPS location—but that probable cause and exigent circumstances can make the warrantless ping reasonable.

CourtSupreme Judicial Court of Massachusetts
DecisionApril 23, 2019
Majority OpinionJustice Kafker
ConcurrencesChief Justice Gants; Justice Lenk
TechnologyProvider-assisted real-time GPS ping
Constitutional GroundArticle 14, Massachusetts Declaration of Rights
InvestigationFatal shooting; armed suspect
Initial ProcessProvider emergency request
Core HoldingGovernment-induced ping was a search
ExceptionProbable cause and exigent circumstances
DispositionSuppression order reversed
Last ReviewedAugust 30, 2026

Executive Summary

The Case in One Paragraph

Hours after a fatal shooting, police had an eyewitness identification of the defendant, his cell-phone number, and information that he still possessed the sawed-off shotgun. Officers submitted an emergency request to the provider. At police direction, the provider caused the phone to generate and transmit GPS coordinates—a “ping”—placing it near the home of the defendant's former girlfriend. The Massachusetts Supreme Judicial Court held that this government-induced, real-time location acquisition was a search under Article 14 of the Massachusetts Declaration of Rights. The court nevertheless reversed the suppression order: officers had probable cause, and the immediate risks posed by an armed murder suspect supplied exigent circumstances. The decision did not resolve the federal Fourth Amendment question.

Core RuleWhen police cause a cell phone to reveal its present location, the resulting location acquisition is a search under Article 14. A warrant is ordinarily required, but the search may proceed without one when officers have probable cause and specific exigent circumstances make obtaining a warrant impracticable.

Almonor is especially important because it separates two questions that are often blurred: first, whether the technique is a search; and second, whether that search is unreasonable. The court answered “yes” to the first question and “no” on the facts of this emergency.

Key Holdings at a Glance

A Ping Was a SearchPolice caused the phone to generate and transmit precise, real-time location information that the user did not voluntarily produce.
Article 14 ControlledThe court resolved the case under the Massachusetts Constitution and did not decide the federal Fourth Amendment issue.
Probable Cause ExistedAn eyewitness identified the defendant as the shooter, and an accomplice connected him to the phone and the shotgun.
Exigency ExistedAn armed murder suspect remained at large, creating concrete risks of violence, escape, and destruction or concealment of evidence.
Suppression Was ReversedBecause the warrantless ping was reasonable under the exigent-circumstances exception, the location-derived evidence was not suppressed.
One Ping Was Not Historical CSLIThe six-hour historical-CSLI threshold discussed in earlier Massachusetts law did not govern a police-induced real-time GPS request.

Fatal Shooting and Emergency Location Request

At approximately 5:19 p.m. on August 10, 2012, police responded to a fatal shooting in Brockton, Massachusetts. An eyewitness told investigators that the defendant had fired a sawed-off shotgun at the victim and fled. The eyewitness later identified the defendant from a photographic array.

An accomplice gave officers the defendant's cell-phone number and reported that he still possessed the shotgun. By approximately 11 p.m., police sent the cellular provider its form for exigent requests. The form described an outstanding murder suspect who had shot and killed the victim and still had the weapon.

When the provider did not immediately respond, an officer called its law-enforcement line around midnight. The provider then pinged the phone and supplied GPS coordinates. Mapping placed the device in the general area of a Brockton street where officers knew the defendant's former girlfriend lived.

The Constitutional EventThe case did not concern passive review of a previously existing business record. Police requested affirmative provider action that caused the phone to disclose where it was at that moment.

What a Provider-Assisted Ping Does

A provider-assisted ping can cause a powered-on cellular device to determine or report its current location. The method and precision vary by provider, network, handset, and request. In Almonor, the provider caused the phone to generate GPS coordinates and transmit them without any voluntary action by the user.

TechniqueSource of LocationConstitutional Focus
Historical CSLIProvider records of earlier cell-site connectionsDuration, aggregation, third-party doctrine, and warrant process
Prospective CSLINew or developing network-location informationReal-time tracking, duration, and judicial authorization
Provider GPS pingDevice coordinates generated or transmitted after a government requestGovernment causation, precision, exigency, and particularity
Cell-site simulatorGovernment equipment induces nearby devices to interactSearch authority, disclosure, minimization, and third-party collection
Voluntary emergency locationUser, caller, or device intentionally sends locationConsent, scope, reliability, and purpose of disclosure
Describe Capability, Not BrandingApplications and reports should explain what the provider or device was asked to do, when the location was generated, the expected precision, and how many updates were requested. Labels such as “ping,” “locate,” or “emergency data” are not substitutes for a technical description.

Government Action and Device Manipulation

The court emphasized that law enforcement did more than ask the provider for information already in its files. Police initiated a process that caused the defendant's device to disclose data. The user did not dial a number, activate a location service, or otherwise choose to transmit the coordinates.

This focus on government causation makes the decision adaptable to new technologies. The constitutional inquiry does not turn entirely on the provider's internal architecture. It asks whether the government prompted a personal device or service to generate information revealing the person's location.

Do Not Overread the HoldingAlmonor does not establish that every provider record request or every isolated location datum is identical. Its holding concerns police-induced, real-time location generation, and its reasoning arises under Massachusetts Article 14.

Why the Historical-CSLI Duration Rule Did Not Apply

Massachusetts precedent had distinguished brief acquisition of historical CSLI from longer-term records, including a rule in Commonwealth v. Estabrook concerning six hours or less of historical CSLI. The Commonwealth argued that a single ping was less intrusive than that period of historical information.

The court rejected the analogy. Historical CSLI consists of records generated through past network activity. The ping in Almonor was a police-induced demand for present GPS information. Because the acquisition method and privacy intrusion were different, the historical-CSLI duration threshold did not control.

FeatureHistorical CSLIAlmonor Ping
TimingReconstructs prior movement or presenceReveals current device location
Record statusOrdinarily exists before police requestGenerated or transmitted because police requested it
User activityOften tied to prior network connectionsNo contemporaneous voluntary action required
Key scope issueLength and aggregation of historical recordsGovernment causation, precision, frequency, and immediacy

Probable Cause Supported the Search

By the time officers requested the ping, their evidence established a fair probability that the defendant had committed the shooting and that locating his phone would locate him or evidence of the offense. An eyewitness described the shooting and identified the defendant from a photo array. An accomplice supplied the phone number and said the defendant remained armed with the sawed-off shotgun.

The court evaluated the collective facts available to officers, not the emergency form in isolation. Those facts connected the offense, the suspect, the device, and the evidence sought.

NexusProbable cause for a location request requires more than probable cause that a person committed a crime. The affidavit or documented record should also connect the person to the device and explain why locating that device will likely advance the authorized objective.

Exigent Circumstances Made the Warrantless Ping Reasonable

The court found a genuine emergency. Officers were searching for a person identified as the perpetrator of a recent killing. He reportedly remained armed with a sawed-off shotgun. Delay created risks that he would flee, use the weapon again, conceal or destroy evidence, or endanger officers and the public.

Exigency is fact-specific. A provider's willingness to process an “emergency” request does not itself establish a constitutional exception. The operative question is whether the facts known at the time created a compelling need for immediate action and made the delay necessary to obtain a warrant unreasonable.

Exigency FactorFacts in Almonor
Gravity of offenseA fatal shooting had occurred only hours earlier
Weapon and dangerThe defendant reportedly still possessed a sawed-off shotgun
Reliable identificationAn eyewitness identified the defendant from a photo array
Flight or concealmentThe defendant had fled and his location was unknown
Evidence riskThe murder weapon could be moved, hidden, or used again
Scope of requestOfficers sought a present location to apprehend the armed suspect
Operational LessonDocument the emergency in real time: who supplied each fact, why the information was credible, what danger existed, why delay mattered, what location data were requested, and when the emergency ended or judicial process became practical.

Consent to Enter, Protective Sweep, and Later Warrant

The coordinates did not themselves authorize entry into a home. They led officers to the general area of the former girlfriend's residence. The homeowner consented to police entry, and officers found the defendant behind a locked bedroom door.

During a protective sweep, officers observed a sawed-off shotgun and a bulletproof vest in plain view. They secured the residence and obtained a search warrant before seizing evidence.

Separate Each Legal StepLocation authority does not automatically authorize entry, arrest inside a home, a protective sweep, or evidence seizure. Agencies should identify and document the distinct legal basis for every step after the location return.

A Search Is Not Automatically an Unreasonable Search

The motion judge suppressed the evidence after concluding that the ping was unlawful. The Supreme Judicial Court agreed that the ping was a search but disagreed that it violated Article 14. Probable cause and exigent circumstances brought the search within a recognized warrant exception.

QuestionAlmonor Answer
Did government conduct implicate Article 14?Yes. Causing the phone to reveal its real-time GPS location was a search.
Was a warrant ordinarily required?Yes. The court treated a warrant as the ordinary rule for this location search.
Was probable cause present?Yes. The eyewitness, accomplice, phone attribution, and weapon information supplied it.
Did an exception apply?Yes. The armed murder suspect and immediate safety and evidence risks created exigency.
Was suppression required?No. The search was reasonable, so the suppression order was reversed.
Doctrinal DisciplineAlways analyze search status, probable cause, warrant authority, exceptions, scope, causation, and remedy as separate questions.

Almonor, Tracey, Carpenter, and Augustine

CaseLocation DataConstitutional BasisPrincipal Result
Commonwealth v. AlmonorPolice-induced real-time GPS pingMassachusetts Article 14Search; reasonable under probable cause and exigency
Tracey v. StateReal-time CSLI used to track a phoneFourth AmendmentSearch; pen-register order insufficient; suppression
Carpenter v. United StatesAt least seven days of historical CSLIFourth AmendmentSearch; warrant generally required
Commonwealth v. AugustineTwo weeks of historical CSLIMassachusetts Article 14Search; warrant based on probable cause required
State v. EarlsProvider-assisted live phone locationNew Jersey ConstitutionReasonable expectation of privacy; warrant generally required

Carpenter expressly left real-time CSLI unresolved. Almonor fills part of that gap under Massachusetts law, while Tracey and Earls supply important but jurisdiction-specific approaches.

Current Operational Rule

Massachusetts officers should treat a request that causes a phone to disclose its present location as an Article 14 search. When time permits, obtain a warrant supported by probable cause that expressly describes the device, technique, requested precision, duration, frequency, and objective.

When a true emergency makes advance judicial process impracticable, officers may rely on exigent circumstances if probable cause also exists. The request must remain reasonably limited to the emergency, and investigators should transition to a warrant when the immediate need ends or continued tracking becomes necessary.

Jurisdiction MattersAlmonor is binding Massachusetts constitutional law, not a United States Supreme Court decision. Federal circuits and other states may classify real-time pings differently or impose additional statutory and warrant requirements.

Practical Guidance for Investigators and Agencies

Identify the Provider ActionState whether the request causes a GPS fix, prospective CSLI, periodic updates, or another device-generated return.
Establish Device AttributionRecord why officers believe the target possesses or controls the identified phone.
Build the Crime NexusExplain why locating the device will probably locate the suspect, protect a person, recover evidence, or accomplish another lawful objective.
Document ExigencyUse concrete facts about immediacy and danger; do not rely only on the seriousness of the offense.
Limit the RequestSpecify the minimum precision, number of pings, update interval, duration, and stopping event needed.
Preserve the Full RecordKeep the form, call log, provider response, coordinates, maps, timestamps, accuracy information, and operational decisions.

Emergency Ping Checklist

  1. Identify the emergency: record the specific threat to life, serious injury, escape, or destruction of critical evidence.
  2. Record the timeline: document when the event occurred, when each fact became known, and why immediate action is required.
  3. Establish probable cause: connect the suspect to the offense, the phone to the suspect, and the requested location to the lawful objective.
  4. Assess source reliability: identify witnesses or informants and the basis for crediting their information.
  5. Explain why a warrant cannot be obtained in time: describe the practical risk of delay, including available remote or on-call procedures.
  6. Name the technique: distinguish GPS coordinates, prospective CSLI, a single ping, or recurring updates.
  7. Use the narrowest effective scope: request only the precision, frequency, and duration necessary for the emergency.
  8. Obtain required approvals: follow provider, prosecutor, supervisor, statutory, and agency-policy requirements.
  9. Log each use: preserve submission times, calls, responses, maps, dissemination, and operational action.
  10. Reassess continuously: stop when the emergency ends and obtain a warrant before materially expanding or extending the tracking.

Real-Time Location Warrant Checklist

  1. Identify the telephone number, device identifiers, account, and provider.
  2. Provide facts showing the target uses or controls the device.
  3. Establish probable cause for the offense and a nexus between location data and the evidence or person sought.
  4. Describe exactly what the provider and device will be asked to do.
  5. Specify whether the return may include GPS, cell-site, Wi-Fi, Bluetooth, or other location sources.
  6. Define the authorized duration, number of pings, update frequency, precision, and geographic or event limits.
  7. Address the possibility that tracking will reveal presence inside a home or another sensitive location.
  8. Include clear termination conditions, return requirements, and handling of unrelated or third-party information.
  9. Request provider records needed to authenticate and explain the location method and accuracy.
  10. Preserve a contemporaneous operational log and promptly return to court for any material expansion.

Litigation and Discovery Checklist

  1. Determine whether the data preexisted the request or were generated because of government action.
  2. Identify the exact location technology, precision, frequency, duration, and provider workflow.
  3. Compare the officer's request, provider form, telephone communications, response, and actual investigative use.
  4. Evaluate the constitutional source: Fourth Amendment, state constitution, or both.
  5. Analyze device attribution and the nexus between the offense, phone, target, and requested location.
  6. Reconstruct the emergency timeline using facts known at the moment of the request.
  7. Test whether less intrusive or timely judicial alternatives were realistically available.
  8. Separate the legal bases for location acquisition, home entry, protective sweep, seizure, and later search.
  9. Trace how the location information produced later observations, statements, arrests, or physical evidence.
  10. Preserve raw coordinates, maps, timestamps, provider certifications, accuracy records, and officer notes.

Frequently Asked Questions

What did Commonwealth v. Almonor hold?

The Massachusetts Supreme Judicial Court held that police conducted an Article 14 search when they caused the defendant's phone to transmit its real-time GPS location.

Was the evidence suppressed?

No. Although the ping was a search, officers had probable cause and exigent circumstances. The court reversed the suppression order.

What created the exigency?

Police were pursuing a recently identified murder suspect who reportedly still possessed the sawed-off shotgun used in the killing, creating immediate risks of violence, flight, and loss of evidence.

Did the court decide the Fourth Amendment question?

No. The court rested its decision on Article 14 of the Massachusetts Declaration of Rights.

Was this historical CSLI?

No. The provider affirmatively caused the phone to generate and transmit its present GPS coordinates in response to the police request.

Does one ping avoid constitutional scrutiny?

Not under Almonor. The court rejected reliance on a historical-CSLI duration rule because a government-induced real-time ping was a different kind of acquisition.

Does an emergency provider form itself authorize a search?

No. Provider procedures do not create a constitutional exception. Officers must establish probable cause and facts supporting a recognized exception such as exigent circumstances.

Did the location ping authorize entry into the residence?

No. The court's account identified homeowner consent as the basis for entry, followed by a protective sweep and a later search warrant.

Primary Authorities and Current Law

Commonwealth v. Almonor, 482 Mass. 35, 120 N.E.3d 1183 (2019)
Massachusetts Supreme Judicial Court opinion holding that the police-induced real-time GPS ping was an Article 14 search but was reasonable because probable cause and exigent circumstances existed.
Read Commonwealth v. Almonor
Commonwealth v. Augustine, 467 Mass. 230 (2014)
Massachusetts decision recognizing Article 14 protection for an extended period of historical CSLI.
Read Commonwealth v. Augustine
Carpenter v. United States, 585 U.S. 296 (2018)
United States Supreme Court decision holding that acquisition of the historical CSLI at issue was a Fourth Amendment search while leaving real-time CSLI unresolved.
Read Carpenter
Tracey v. State, 152 So. 3d 504 (Fla. 2014)
Florida Supreme Court decision addressing police use of real-time cell-phone location information.
Read Tracey v. State
Massachusetts Digital Evidence Guide
Massachusetts guidance collecting current digital-evidence authorities, including location-information decisions.
Review the Massachusetts Digital Evidence Guide

Final Assessment

Commonwealth v. Almonor gives agencies a disciplined way to analyze real-time phone-location emergencies. A police-directed provider ping is not merely a convenient records request; under Massachusetts law, it is a search because the government causes a personal device to reveal where it is.

At the same time, calling the technique a search does not disable urgent law enforcement. The warrant requirement accommodates genuine emergencies. The constitutional safeguard is careful documentation of probable cause, immediacy, scope, and the transition from emergency action to judicial process.

Shield Practice RuleTreat a provider-assisted real-time ping as a location search; identify the precise device and provider action; establish probable cause connecting the offense, target, phone, and location objective; obtain a warrant when practicable; when exigency requires immediate action, document the danger and timeline in concrete terms, limit the request to the emergency, reassess continuously, preserve every provider and mapping record, and identify separate authority for entry, sweep, arrest, and seizure.

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This monograph is provided for training and general informational purposes. It is not legal advice and does not replace review of the complete opinions, current statutes, controlling federal and state authority, provider requirements, agency policy, technical documentation, or consultation with prosecutors and agency counsel.

© 2026 Shield Public Safety Training. All rights reserved. Reviewed August 30, 2026.