State v. Tate
The Wisconsin Supreme Court decision treating a probable-cause cellphone-tracking order as a functional warrant for provider location data and cell-site-simulator use.
Executive Summary
Investigators linked a prepaid cellphone to a Milwaukee homicide suspect and obtained an order authorizing a pen register, trap-and-trace information, provider records, tower activity, GPS information if available, and identification of the phone’s physical location. Provider data narrowed the search area; police then used a cell-site simulator to locate the phone inside an apartment building and ultimately in the home of the suspect’s mother. The Wisconsin Supreme Court assumed without deciding that this tracking was a search and that a warrant was required because it led police to a phone inside a residence. It nevertheless held the search reasonable. Although labeled an “Order,” the authorization functioned as a warrant: it was issued by a neutral judge, rested on probable cause, identified the target phone and tracking objective, and imposed a 60-day limit. The court also found no need for a statute specifically authorizing the technology. The dissent would have squarely recognized a search and demanded clearer statutory and constitutional limits.
Key Holdings at a Glance
Homicide, Prepaid Phone, and Identification
On June 9, 2009, a man entered a Milwaukee store, purchased a prepaid cellphone, identified himself as “Bobby,” and said he had recently left prison. Surveillance video then showed the man leave the store and shoot two people, killing one victim.
The clerk and store records connected a particular cellphone number to that transaction. Investigators used the purchase, video, witness information, and records to seek judicial authority to identify the phone’s location and find the shooter.
After tracking led officers to an apartment, they found Bobby Tate sleeping in a rear bedroom. Officers observed a striped polo, a shoe appearing to bear blood, and the target phone. Tate was arrested and later pleaded no contest to first-degree reckless homicide.
What the Court Order Authorized
The application sought a pen register and trap-and-trace device plus provider-held information. The order covered subscriber information, incoming and outgoing call details, cell-tower activity and location, text-message header information, toll information, GPS location if available, and procedures to identify the phone’s physical location.
| Feature | Order Treatment | Modern Drafting Lesson |
|---|---|---|
| Target | Specified cellphone number | Add provider, device identifiers, and facts showing current possession |
| Information | Multiple categories of records and location information | Separate provider disclosure from direct government signaling |
| Method | Procedures to identify physical location | Name the simulator and explain how it interacts with phones |
| Duration | 60 days | Use the shortest justified period and stopping conditions |
| Place | Not a traditional premises description | Address precision and entry into protected locations |
Provider Tower Data and the Cell-Site Simulator
Provider information showed the phone communicating through three towers and sectors. Officers mapped the probable area and then used a vehicle-mounted directional antenna associated with a cell-site simulator.
According to the record, the equipment responded only to the target phone’s electronic serial number. Signal strength helped officers narrow the location to an apartment building and then to its southeast portion. Officers checked several apartments before arriving at the home of Tate’s mother.
The Court Assumed a Search Without Deciding It
The State conceded for purposes of the appeal that the tracking constituted a search. The court accepted that premise without creating a categorical rule for all cell-site information or simulator operations.
It likewise assumed a warrant was necessary because the technique led officers to Tate’s location inside his mother’s home. The decision therefore turned on whether the existing order satisfied warrant requirements, not on whether no warrant was needed.
Why the Order Functioned as a Warrant
The majority looked to substance. A judge issued the order before the search, the supporting affidavit established probable cause, and the authorization described the target and permitted tracking for a defined period.
A document need not contain the word “warrant” to provide warrant-level protection. Conversely, merely labeling a document a warrant cannot cure missing probable cause, lack of particularity, or absence of a neutral judicial determination.
Probable Cause to Locate the Phone
The video showed the purchaser commit the shooting immediately after buying the phone. The clerk described the purchaser, recalled the name “Bobby,” and connected the transaction to store records identifying the phone.
Those facts supported a fair probability that locating the phone would help officers apprehend the shooter and produce evidence connecting the phone’s possessor to the crime. The nexus was therefore between the identified phone, the homicide, and the person officers sought.
Particularity: Phone, Method, and Time
The court found sufficient particularity because the order identified the target phone by assigned number, described the circumstances in which tracking procedures could be installed and used, and limited authorization to 60 days.
The majority analogized to guidance in United States v. Karo concerning beeper warrants: identify the object to which the device relates, state the circumstances supporting use, and limit the period of tracking.
Specific Statutory Authority Was Not Dispositive
Tate argued that no Wisconsin statute specifically authorized the location order. The majority held that a technology-specific statute was unnecessary where the order satisfied constitutional warrant requirements. It also treated the order as a criminal subpoena for information held by the provider and concluded that it complied with the spirit of the then-existing warrant and subpoena provisions.
Wisconsin enacted more specific location and tracking statutes in 2014, after the 2009 investigation. Those later provisions did not govern the historical operation.
Tracking to a Residence and Entry Authority
The tracking ultimately indicated that the phone was inside a residential building. Testimony conflicted over consent to enter Tate’s mother’s apartment. The Wisconsin Supreme Court’s core tracking analysis did not turn on announcing a broad rule that location authority automatically authorizes home entry.
Location acquisition, premises entry, arrest, seizure of items, and search of phone contents are separate legal events. Each requires its own authority or a recognized exception.
Chief Justice Abrahamson’s Dissent
The dissent would have expressly held that government acquisition of cellphone location information was a search. In its view, people purchase phones for communication, not to provide the government a tracking device.
The dissent criticized the breadth and lack of clarity in the record, including the categories of information available and the 60-day period. It also questioned whether an undefined order provided the statutory and constitutional safeguards demanded by emerging technology.
Its central warning remains influential: courts need accurate technical facts and clear rules before authorizing tools capable of revealing location within private spaces.
Tate Under Current Digital-Location Law
Tate was decided shortly after Riley v. California and four years before Carpenter v. United States. Carpenter’s treatment of historical CSLI does not directly decide every real-time or simulator question, but it reinforces the need to treat detailed digital location information as constitutionally sensitive.
Later simulator decisions have often required warrant-level authority and more explicit disclosure of the technique. Tate remains useful for the functional-warrant principle, probable-cause nexus, and particularity analysis, but it should not substitute for current jurisdiction-specific law.
Practical Guidance for Agencies
Cellphone-Tracking Warrant Checklist
- Identify the offense, suspect, phone number, provider, and known device identifiers.
- Establish probable cause connecting the phone to the suspect and crime.
- Separate historical records, prospective provider data, GPS, and simulator use.
- Name and explain the simulator if direct government operation is requested.
- Specify precision, geographic scope, duration, use schedule, and stopping events.
- Address homes and other constitutionally sensitive locations.
- Prohibit content collection unless separately authorized.
- Define non-target filtering, retention, deletion, and audit requirements.
- Require operational logs, a return, and disclosure of deviations.
- Request extensions only on updated facts and renewed judicial approval.
Provider and Simulator Operations Checklist
- Verify the authorized target and expiration before activation.
- Record the exact equipment, software, configuration, and operator.
- Confirm location-only settings and disable content functions.
- Document each provider response and each direct deployment separately.
- Use the least intrusive precision necessary for the mission.
- Pause before entering a home or other protected place.
- Stop when the target is located, the objective is achieved, or authority expires.
- Preserve logs and delete non-target information as required.
- Report technical anomalies and scope deviations immediately.
- Complete the judicial return, discovery, audit, and after-action review.
Litigation and Discovery Checklist
- Obtain the order, application, affidavit, return, provider process, and all amendments.
- Identify whether the authorization named the simulator or only provider data.
- Reconstruct tower-data analysis and every simulator deployment.
- Determine the device model, settings, precision, duration, and information received.
- Analyze probable cause, nexus, particularity, duration, and judicial neutrality.
- Separate tracking legality from residential entry and subsequent searches.
- Determine whose phone and premises rights are at issue.
- Apply current constitutional and statutory law, not only Tate’s assumptions.
- Review minimization, deletion, candor, and discovery compliance.
- Address remedy doctrines separately from prospective authorization.
Frequently Asked Questions
What did State v. Tate hold?
It held that the tracking was reasonable because the probable-cause court order functioned as a constitutionally valid warrant.
Did Tate decide that Stingray use is a search?
No. The court assumed search status without deciding it.
Why was the order sufficiently particular?
It identified the target phone, described the tracking objective and circumstances, and imposed a 60-day limit.
Did the order expressly use the brand name Stingray?
The decision treated the authorized location procedures as encompassing the operation, but modern best practice is to identify the simulator and explain the direct interaction expressly.
Was a technology-specific Wisconsin statute required?
The majority said no because the order independently satisfied constitutional warrant requirements. Current statutes must still be followed.
Did location authority automatically authorize entry into the apartment?
No. Location tracking and entry into protected premises require separate legal analysis.
Why is the dissent important?
It pressed the court to recognize cellphone location acquisition as a search and demanded clearer limits for technology capable of locating people inside private spaces.
Primary Authorities and Current Law
Wisconsin Supreme Court opinion treating the tracking order as a functional warrant while assuming the search question.
Read State v. Tate
Supreme Court decision addressing electronic location monitoring inside a home and beeper-warrant guidance.
Read United States v. Karo
Supreme Court decision recognizing the exceptional privacy implications of modern cellphones.
Read Riley v. California
Supreme Court decision requiring a warrant for acquisition of historical CSLI in the circumstances presented.
Read Carpenter v. United States
Later state high-court decision discussing Tate’s functional-warrant reasoning.
Read State v. Copes
Final Assessment
State v. Tate is a functional-warrant case, not a broad constitutional approval of cell-site simulators. It illustrates how probable cause, a clearly identified target phone, a defined locating objective, and a time limit can make a judicial order operate as a warrant despite its title.
Its limits are just as important. The court assumed rather than decided the search question, the operation occurred under 2009 facts and law, and modern doctrine demands more explicit treatment of digital-location precision, direct device interaction, non-target information, and residential thresholds.