Chicago Police DepartmentGeneral Order G03-01-03
Illinois State Police Emergency Radio Network (ISPERN)
Issue Date:01 August 1997Effective Date:02 August 1997
Index Category:Field Operations
This directive:
  • A.outlines the purpose of the Illinois State Police Emergency Radio Network (ISPERN).
  • B.defines the procedures and responsibilities for the use of the ISPERN radio by sworn members of the Department.
II.General Information
  • A.The Illinois State Police Emergency Radio Network (ISPERN):
    • 1.provides personnel in police mobile units with an inter-agency communication capability for police activity of an emergency nature within the State of Illinois.
    • 2.operates on a radio frequency assigned to the Illinois State Police by the Federal Communications Commission.
    • under the control of the Director of the Illinois State Police.
  • B.Along with the majority of other police vehicles in Illinois, a limited number of Department vehicles are equipped with ISPERN radios. These vehicles are assigned to:
    • 1.districts that border a suburb or suburbs.
    • 2.other selected units.
  • C.A Control Point is a dispatch center possessing a base station transmitter licensed to operate on the ISPERN frequency. The Department's ISPERN Control Point is:
    • 1.designated "Chicago P.D."
    • 2.operated by the Office of Emergency Management and Communications (OEMC) Point-to-Point dispatcher.
  • D.To accomplish the objectives of ISPERN, specific criteria for allowable communications have been established. The following eight types of communications are listed in priority ranking:
    • 1.emergency;
    • 2.disaster;
    • 3.pursuits;
    • 4.criminal/traffic offense or missing persons;
    • 5.hit alerts;
    • coordination;
    • 7.itinerant;
    • 8.testing.
III.Frequency Allocation
  • A.All mobile (installed) ISPERN radios have only the F-1 frequency, while all portable ISPERN radios are also equipped with the F-2 frequency.
  • B.The F1 or first frequency on the ISPERN radio unit is the ISPERN channel. The F1 frequency will:
    • used for field operations involving other police jurisdictions.
    • used primarily for the transmission of flash messages of incidents involving both the Department and suburban police.
    • 3.normally not be used during field operations that only involve the Chicago Police Department.
  • C.The Department is authorized to use the F2 or second frequency for:
    • 1.field operations that do not involve other law enforcement agencies.
    • 2.communication on a closed network during disorders, disasters, demonstrations, etc.
    • 3.effecting the apprehension of a person or persons suspected of being engaged in criminal activity.
IV.Broadcast Criteria
  • A.The unit sending an ISPERN message must have reasonable grounds to believe that a crime did occur, is occurring, or is about to occur.
    • 1.A report from the public shall be considered reasonable grounds, providing that the complainant's name, address and phone number is received.
    • 2.Confirmed alarm notifications may be broadcast.
  • B.An ISPERN message should contain:
    • 1.a one or two word description to identify the nature of the incident or offense.
    • 2.the exact location of the incident or offense.
    • 3.the time of the incident or offense or time of last contact.
    • 4.offender/vehicle description(s).
      Flash Messages should be broadcast within one hour from the time that the crime was committed.
  • C.Unless extenuating circumstances exist, the following do not qualify for dispatch over the ISPERN system in the Chicago area:
    • 1.missing persons;
    • 2.theft of services;
    • 3.theft under $300 U.S.C.
V.Broadcast Procedures
  • A.Members wanting to issue an emergency flash/wanted message over the ISPERN will direct their transmission to the City-wide 3 dispatcher. The City-wide 3 dispatcher will then relay the information to the point-to-point dispatcher monitoring the ISPERN frequency.
  • B.Required pursuit information:
    • 1.speed;
    • 2.location and direction of travel;
    • 3.vehicle and/or personal description;
    • 4.reason for pursuit (original offense).
      Members will adhere to the Department's policy involving pursuits.
  • C.The originating officer or agency must notify the Control Point whenever a recovery or apprehension is made within 10 hours of origination so that a brief cancellation message may be given on ISPERN.
  • D.Transmissions from the Control Point dispatcher to Department units equipped with ISPERN radios are called "Dispatch Alerts." A Dispatch Alert is:
    • 1.the ISPERN equivalent to an OEMC all-call broadcast.
    • 2.broadcast to ISPERN equipped police units within a specific geographical location.
    • 3.preceded by an alert tone (a one second rapid singular tone).
VI.Broadcast Categories
The four Criminal/Traffic Offense categories appropriate for broadcast over ISPERN are:
  • A.Type A - Wanted or Stolen:
    • used when probable cause for arrest has been established by the originating authority.
    • 2.shall indicate "Complaint Signed" or "Complaint Will Be Signed" for all traffic offenses.
      Complaint signed or will be signed is assumed in all criminal acts (e.g. stolen vehicle) and need not be stated in the broadcast.
  • B.Type B - Wanted Investigation:
    • used when probable cause for arrest has NOT been established; however, reasonable grounds to justify an investigative stop (Terry vs. Ohio) has been established by the originating authority.
    • 2.shall indicate "Complaint has NOT been signed; however, reasonable grounds to justify an investigative stop has been established."
    • 3.may include a statement, "Notify originating authority prior to stopping the suspect."
    • 4.must include an immediate notification by the Control Point dispatcher to the originating authority if the suspect is observed or stopped.
  • C.Type C - Traffic Offense:
    • used when a traffic offense (e.g., DUI, Reckless Driving, Drag Racing, etc.) has been reported and neither probable cause for arrest nor reasonable grounds to justify an investigative stop has been established, e.g., the complainant will not sign a complaint.
    • 2.shall indicate "Make your own case."
  • D.Type D - Intelligence Information:
    • used when:
      • a.neither probable cause for arrest nor reasonable grounds to justify an investigative stop has been established.
      • b.the originating authority has developed intelligence information which, when combined with other facts known to an officer observing the suspect, could result in reasonable grounds to justify an investigative stop or probable cause for arrest.
    • 2.will be used if the information relates to criminal intelligence (e.g., suspicion of possible criminal activity, possible threats against police officers, illegal transportation of drugs, large amounts of currency, weapons or aliens, etc.).
    • 3.may include the statement: "Notify the originating authority prior to stopping the suspect."
    • 4.will indicate "Do not initiate enforcement action based solely on this information" or "Maintain surveillance, do not stop."
VII.Mobile to Mobile Communications with Other Law Enforcement Agencies on ISPERN
  • A.Department field units may talk with other police agencies' field units on ISPERN without going through a Control Point dispatcher provided the transmissions are short and serve a police purpose.
  • B.The procedure for inter-agency, car-to-car communication requires the Department field unit to:
    • up the other law enforcement unit, e.g., "Is there a Bridgeview unit monitoring ISPERN?"
    • 2.identify himself, e.g., "Chicago P.D. Beat 811."
    • 3.give the message.
    • 4.sign off using the FCC call sign KN 3600.
VIII.Non-ISPERN Equipped Department Field Units Sending ISPERN Messages
Any Department field unit not equipped with an ISPERN radio may initiate an ISPERN broadcast by:
  • A.sending a message to the City-wide 3 dispatcher.
  • B.requesting that the City-wide 3 dispatcher forward the message to the point-to-point dispatcher for broadcast on ISPERN.
Matt L. Rodriguez
Superintendent of Police
95-081 BJD/PS(HEH)