Geofence & Advanced Location Tower Dump

Tools that help solve impossible cases, done the right way

An easy solution to a difficult problem

It's just past midnight and three drive-by shootings just occurred in your city. As luck would have it, no witnesses can be found to identify the vehicle and the victims are not talking... Lacking leads, this case could be unsolvable. An Advanced Location Tower Dump or geofence warrant may be the only solution.

How does Advanced Location Tower Dumps and Geofence Warrants Work?

Warrant Builder makes Advanced Location Tower Dumps and geofence warrants simple with a point, click, warrant workflow. It brings years of warrant writing and cybercrime experience into one platform, helping officers handle complex investigations. The system supports both tower dumps and Google geofence warrants, with built-in mapping and tools to review the results.

A geofence warrant is a legal order that allows law enforcement to collect data from devices within a defined area and time. This can include GPS locations, timestamps, and related data from phones, wearables, and connected vehicles. Investigators create a virtual boundary using GPS coordinates. AT&T and T-Mobile require a radius from a single point, while Google allows shapes like squares or polygons. For example, in a drive-by shooting, investigators could set boundaries around multiple related locations. If the same device appears in all of them, it may identify a suspect.

Multi-phase warrant process

To comply with the requirements of United States v. Chatrie, geofence warrants follow a phased approach. Breaking the process into separate phases helps protect the privacy of people who are not involved.

When Google identifies devices within the geofence, it assigns each one an anonymized identifier. This identifier represents a single device only during the warrant process.
AT&T and T-Mobile use IMSI numbers as their version of an anonymized ID. After the process is complete, Google deletes these identifiers.

Unlike other types of anonymized data online, an obfuscated ID cannot be used to identify a device or person by anyone outside of Google. In the same way, only the telecom providers can link an IMSI number to a specific customer.

Phase 1

Create your initial search areas.

Phase 2

See how specific devices entered or left your crime scene.

Phase 3

Unmask the relevant devices with basic subscriber information.

Warrant Builder's approach

Warrant Builder walks you through each phase of the process and adds the required language based on your investigation. It does more than support geofence warrants. It maps your warrant returns directly within the platform, so there is no need for outside tools.

The process is reduced to a few key questions, allowing you to focus on probable cause while the system handles the rest.

Phase 1 - Initial Search Area

The initial search area is the first phase of the warrant and defines the location or locations to be searched. When possible, using more than one location is recommended to identify devices that appear in both areas. For example, this could include where a car was stolen and where it was later found. A shorter time window will produce more accurate results.

Warrant Builder geofence warrant tool showing Phase 1, reverse location anonymized ID, mobile phones

Phase 2 - Movement Information

Next comes the mapping of record returns from Google. As seen below, several devices were identified by their Anonymized IDs. These temporary numbers are assigned to represent mobile phones located within the search area.

Example Anonymized ID 010101BD55464DAC6520C124E72FF65A6E7D15F2F4E4D51F913A5DEBAFF6F3891341012D8950D7

TheThe investigator selects the devices they believe are relevant and drafts a new warrant for those specific devices. The warrant requests location data from before and after the initial time period. This helps show how the device arrived at the crime scene and where it went afterward.

Warrant Builder geofence warrant tool showing Phase 3, reverse location anonymized ID, mobile phones, movement.

Phase 3 - Device Unmasking

After reviewing Phase 2 records from Google, AT&T, or T-Mobile, the investigator can better understand how each device moved. The data may show that a device only passed near the crime scene and kept going. It could belong to a delivery driver who drove through the area and made frequent stops. In some cases, the data may show a device entering the crime scene and staying there for an unusual amount of time. Based on this, the investigator may rule out devices that do not appear suspicious and focus on the one that does.

In Phase 3, the investigator requests that the provider identify the remaining device by providing subscriber details such as the account holder’s name, email address, and device information.

Benefits of Geofence Warrants

Enhancing Investigation Efficiency: Geofence warrants can significantly expedite investigations by allowing law enforcement to focus on individuals who were present within a specific area during a particular timeframe. This targeted approach helps narrow down suspects and potentially leads to faster resolution of cases.
Gathering Evidence: Geofencing provides investigators with access to critical device location and movement patterns. This evidence can strengthen criminal cases, verify alibis, establish connections between suspects, and unravel intricate criminal networks.
The warrant of last resort: Geofence Warrants are primarily used when all other leads are exhausted to solve the unsolvable case. They serve as a digital witness to the crime, possibly identifying involved persons. Knowing how that phone came into a crime scene and where it traveled to after may be the break in the case that law enforcement never would have had without the geofence.

Disadvantages of Geofencing

Privacy Concerns: One of the main concerns surrounding geofencing is the potential invasion of privacy on unrelated persons. A mobile phone located within a crime scene likely belongs to one of three categories of persons: suspects, victims or witnesses.
False Positives: Geofence warrants are not foolproof and can generate false positives, identifying innocent individuals in criminal investigations. False positives could be due to poor location accuracy reporting by a mobile phone or the devices connection to Wi-Fi instead of mobile data GPS coordinate reporting.

Quick & Accurate

Search warrants are required to be specific, and Warrant Builder's Geofence tool maps your search area coordinates within 4" of accuracy.

Testify with confidence that you have defined the search area as accurately as possible. This level of accuracy will help with Judges that don't want infringement on neighbors.