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Search Warrant
<br />Page 14 of 19
<br />know gang members to adopt patterns of criminal activity and engage in such on a continual basis with repeated
<br />regularity.
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<br />I have a general understanding of how the cellular telephone network operates. I am aware that cell sites (towers)
<br />are strategically placed by cellular service providers, to provide a seamless operation so people can travel
<br />virtually anywhere and make or receive an uninterrupted call, send or receive text messages, or initiate a data
<br />session via their cellular phone. Usually, cell sites will be mounted high on a large pole, building, or other structure
<br />which provides line of sight with the population below. Cell sites are typically divided into sectors, which are made
<br />up of antennas connected to cellular radio transceivers. Each sector is mounted on the cell site and faces a
<br />specific direction to provide maximum cellular coverage for the people in the area. The range of the cell site and
<br />sectors depends on many factors to include environmental and geographic factors and whether it is located in a
<br />highly populated, urban environment or desolate rural area. Cell site location information (CSLI) does not provide
<br />an exact location of a cell phone; the basic call detail record data only provides the physical location of the cell
<br />site (latitude and longitude) and a direction (azimuth) the antennas are facing from the cell site.
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<br />I am aware when a person either initiates or receives a voice call, text message, or a data session (usage even t)
<br />from their cellular device, the device broadcasts signals to the cell site that routes its communications. These
<br />signals include a cellular device’s unique identifiers as well as details about the usage event. I am also aware
<br />cellular service providers collect and store these usage event details (transaction records) associated with cellular
<br />phone numbers during the normal course of business. The usage event records, commonly referred to as call
<br />detail records, stored by their respective cell phone company, mostly contain the following information with some
<br />exceptions based on the specific carrier: Date, time, type of event, duration, phone number initiating the usage
<br />event (called, calling), even if caller identification is blocked by the calling party, text message transaction data,
<br />the international mobile equipment identifier (IMEI), the international mobile subscriber identifier (IMSI), IP packet
<br />data session logs, and cell site location and sector information at the beginning and ending of each usage event.
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<br />I am aware cellular service providers maintain specialized location records consisting of engineering data. These
<br />data sets are used by the providers to troubleshoot coverage areas and report back on potential dead spots, all
<br />with the intent to oversee and optimize the cellular network. Specialized location records typically contain data for
<br />every usage event, to include technology details (e.g. voice, text, data), resource usage, and call failure
<br />information. They can also include data for incomplete calls (e.g. denied calls and set-up failures). These records
<br />not only include the basic call detail records, but also an estimation of the target phones location (Latitude and
<br />longitude) with a possible accuracy radius, and/or the distance from the cell site at the time of the usage event.
<br />
<br />Utilizing specialized location records can provide investigators with a much smaller footprint of a target phones
<br />location and could place a target phone within close proximity of a crime scene before, during and after a crime.
<br />Each carrier uses their own nomenclature to describe the technology used to obtain this data including: NELOS
<br />(Network Event Location System) – AT&T-Mobile, RTT (Round Trip Time/Return Trip Time/Real Time Tool) -
<br />Verizon & U.S. Cellular, PCMD (Per Call Measurement Data) – Sprint & U.S. Cellular, and TDOA (Time
<br />Difference of Arrival) or Timing Advance Information – T-Mobile & Metro by T-Mobile. I believe this information is
<br />relevant and material to the investigation as it provides supplemental geo-location information which, while not
<br />precise enough to identify a specific house, is accurate enough to provide block -level accuracy, in some cases.
<br />Investigators can use this information to correlate existing fact patterns and timelines to confirm or refute prior
<br />statements and/or evidence regarding the location of the target device.
<br />
<br />When any person makes or receives a phone call on their cellular phone, the following information for each call is
<br />stored by their respective phone company for at least one year: date, time, duration, phone number dialed or
<br />received numbers (even if caller identification is blocked by the calling party), text message transaction data, IP
<br />packet data session logs, and cellular tower location/sector at the beginning and ending of the call/data session. This
<br />is very basic information and does not provide an exact location of the person nor does it identify the other party.
<br />Cellular towers are strategically placed throughout the world by phone companies in an attempt to provide a
<br />seamless operation so people can travel virtually anywhere and make or receive a call. A typical cellular phone tower
<br />will be mounted up high on a large pole, building, or other structure which provides an unobstructed view of the
<br />population below. Cellular towers are divided into either three or six sectors, depending on the cellular provider. Each
<br />individual sector is mounted on the tower and faces a specific direction to provide maximum cellular coverage for the
<br />people in the area. The range of the tower depends on environmental factors and whether it is located in a highly
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