Inspired by a contest in 1924, Police Chief
R. Lee Heath ordered his staff to investigate the use of radio communications to "more quickly dispatch officers to where they are needed." It was not until Police Chief
Roy E. Steckel, however, that the department was assigned its first
Federal Communications Commission license. On May 1, 1931, KGPL, the LAPD's dedicated radio callsign, began broadcasting at 1712 kHz, just above the commercial radio broadcasting frequencies; this was later changed to 1730 kHz. Any citizen could monitor outgoing police radio traffic on their home sets. The system was "one way" until the mid-1930s when mobile transmitters were installed in patrol units. In 1949, the FCC changed KGPL's callsign to KMA367. This was later changed again at an unspecified point in time; the LAPD's current primary radio callsign is KJC625. Other frequencies are also used for varying divisions and purposes, such as WPLQ343 for talkaround (direct unit-to-unit communications), WPRJ338 for detectives, and WIL868 for tactical operations. KMA367 is still used by a handful of LAPD divisions, but it is no longer the primary radio callsign for a majority of the department.
Emergency calls for police service are handled by the Communications Division. First, an Emergency Board Operator answers calls placed to 911 (with a lower number of operators assigned to the non-emergency 1-877-ASK-LAPD). A call for service is assigned an incident number, which resets to the number 1—citywide—at midnight each night. Upon receiving the
call for service, the Radio Telephone Operator (RTO) will go on the air to broadcast to the division (with the option to simulcast on bureau-wide, geographically adjacent or citywide frequencies). RTOs provide the following information in what is known as a crime broadcast: • A set of beep tones based on call priority (none for low priority, three for priority, four for major priority), • to whom this message is intended (a particular unit, a certain division's units, nearby units, any available units, or all units receiving the transmission), • the type of incident that just occurred (usually per the
California Penal Code, but sometimes an abbreviation established by the Communications Division), • how long ago the incident occurred, • the location or address of the incident, • the number of suspects (if more than one), • a description of the suspect or suspects, their clothing and/or other uniquely identifiable attributes if available, any weapons they may have, • a description of the suspect vehicle or vehicle(s), including type, make, model, color, and license plate number (if suspect is using a vehicle, and if such information is available), • additional details, such as information about the "PR" (person reporting) or simply an order to "monitor comments for additional" (a direction to responding officers to read about the incident on their
mobile data terminals (MDTs)), • a
response code (Code 3 for emergency lights and sirens and Code 2 for no lights and no sirens) • a request for the responding units to identify themselves with their callsigns, and • the incident number and the "RD" or reporting district (a numbered area within the division). A fictitious example of an LAPD dispatch radio transmission would be:Any available Central unit, a 211 just occurred at 714 South Broadway Street. Suspect is a male, white, six-foot seven, approximately 280 pounds; shaved head, black eyes, white shirt, blue jeans. Vehicle is a dark grey late-model Chevrolet Malibu. Weapon used was a semi-automatic handgun. Monitor comments for additional. Units to handle Code 3, identify. Incident number 171 in RD 193.Without using
jargon, this radio transmission is directed to any currently available Central Division unit and reports an
armed robbery at 714 South Broadway Street, followed by the suspect's physical description, vehicle description, and weapon, an order to read information in the MDT, and a request for the responding units to identify themselves using their callsign and respond to the scene with emergency lights and sirens, ending with the call's daily incident number, the 171st call of the day. Additionally, it includes a Reporting District for Central Division's Beat 93. The Central Division is numbered "1", meaning an RD of 193.
Radio codes Source: • Code 1: Answer radio • Code 2: Respond to the call without emergency lights and sirens • Code 3: Respond to the call with lights and sirens • Code 4: No further units needed to respond, return to patrol • Code 4-Adam: No further units needed to respond, suspect not in custody, units already en route to the scene position or patrol in strategic areas near the scene • Code 5: Stakeout, marked police cars must avoid location • Code 5-Edward: Notify Air Support Division personnel of an explosive hazard to low-altitude aircraft • Code 6: Unit conducting field investigation, no assistance required. • Code 6-Adam: Unit conducting field investigation, may need assistance whilst conducting an investigation • Code 6-Charles: Dangerous suspect (usually felony want or warrant reported); units stand-by for assistance • Code 6-George: Unit may need assistance in conducting an investigation concerning possible gang activity, an available Gang Enforcement Detail unit shall respond. • Code 6-Mary: Unit may need assistance in conducting an investigation concerning possible militant activity, units in vicinity shall direct patrol to location. • Code 7: Meal break request • Code 8: Fire reported in area of high fire hazard or threat to firefighting personnel • Code 8-Adam: Units requested to scene of fire for traffic and crowd control • Code 10: Request to clear frequency for broadcast of wanted/warrant information • Code 12: Request to clear frequency for request for information on potential individual arrest warrant • Code 20: Notify media (or media already on scene) • Code 30: Burglar alarm (can be Code 30-Silent) • Code 30-Adam: Burglar alarm, location is monitored with audio by security company • Code 30-Ringer: Ringing burglar alarm • Code 30-Victor: Visual verification burglar alarm • Code 37: Vehicle is reported stolen (Code 6-Charles is given if vehicle license check produces dangerous suspect or felony want/warrant information) • Code 100: Notify other units that a possible escape route of a suspect from a crime scene is under temporary surveillance. • Code Robert-Rifle: Request/notification for deployment of
rifle to/at location. • Code Robert-Slug: Request/notification for deployment of
shotgun to/at location. • Code Sam: Request/notification for deployment of less-than-lethal
Bean bag round-equipped shotgun to location • Code Sam-40: Request/notification for deployment of a 40mm less-than-lethal rubber bullet (grenade) launcher • Code Tom: Request/notification for deployment of
taser to/at location
Radio Communication terms Source: • AC: Aircraft crash • FB: Fallen Balloon • QT: Secrecy required regarding location • 211: Robbery • 311: Indecent exposure • 390: Drunk male • 390W: Drunk female • 415: Disturbance • 459: Burglary • 484: Theft • 484PS: Purse Snatching • 502: Under-the-influence driver • 507: Minor disturbance • 507FC: Firecrackers • 586: Illegal Parking • 586E: Car parked in driveway • Roger: Message received; will comply • Come In: You are being called • Stand By: Wait until a suitable answer is determined-or do not transmit • Go Ahead: Proceed with your message • Repeat: Repeat your message • Out: Out of service; not available for call (used when no other specific code applies and shall be followed by the reason) • Clear: No calls outstanding against unit; available for call • Want: Determine whether a vehicle is wanted or is to be held • No Want: No want or hold on subject or vehicle of inquiry • Warrant: Vehicle warrant information • DMV: Information regarding vehicle registration • Juvenile Check: Determine whether there is want, hold, or criminal record for juvenile subject • End of Watch: Unit has completed tour of duty A unit that responds Code 3 must state their starting location (e.g. intersection or street address), after which the RTO broadcasts a Code 3 notification, announcing the unit number is responding Code 3 from that starting location to the location of the distress call. Typical radio traffic (usually not simulcast citywide) includes the activity generated from traffic stops. A patrol unit may radio control that they are Code 6 on a traffic stop, to which Control will acknowledge. Additional broadcasts will be requests for information on "Cal IDs", or "CalOps" (the numbers that appear at the top of
California Department of Motor Vehicles driver licenses) or on vehicle license plates, the result of which provides all of the expected details about the subject plus important details such as whether or not the licensee has any wants or warrants, FTAs (failure to appear in court) or FTPs (failure to pay a fine), etc. In the case of a vehicle, this information can help check whether or not it is Code 37. Off the air and via MDT, officers can check to whom the vehicle is registered. In the event a Code 6-Charles is broadcast, the unit in question must verify their location, advise if they are Code 4, and the nature of the Code 4 (e.g. suspect in custody, common name, information only or wrong suspect.) A noticeable characteristic of police broadcasts is the expedited nature of crime broadcasts; due to the number of broadcasts that need to be made at any given moment of the day, each transmission is necessarily as brief as possible. As a standard of police professionalism, RTOs are trained to use a tone that is strictly business-like.
Unit callsigns Source: From the perspective of control, each unit is represented by an LAPD-specific callsign. Typically, a callsign is made up of three elements: the division number, the unit type, more specifically the service identification letter and the "beat" number. For example, division 1 is Central Division (or, now, "Central Area"), an "A" is patrol unit with two officers and their patrol area number can be a number like 12. Such a unit would identify themselves as 1A12 (or 1-Adam-12, using the
LAPD phonetic alphabet). There are several types of units, designated by a letter: The immediate supervisor of any patrol officer is called a field supervisor, which typically have beats that end in zero beginning from 2 through 7 (for example, 7-L-60 for a Wilshire Area supervisor). The watch commander is a usually a Lieutenant I at a geographic division. Their radio code always ends in Lincoln-10 (e.g., the watch commander at division 6 or Hollywood Area station is always 6-L-10). The watch commander is responsible for the geographic area (e.g. "Southwest Area") and reports to the area patrol captain I, whose callsign consists of "Commander (Div. Number)A" - therefore a Southwest Area patrol C/O is "Commander 3A". Callsigns ending in "L90" designate the given division's station desk or base radio console.
Staff Unit Designations Radio equipment Officers out of their cars are able to communicate over the air using portable
Motorola radios nicknamed ROVERs ("Remote Out of Vehicle Emergency Radios"). These hand-held radios are currently a mix of the new Motorola APX-8000 and Motorola XTS-5000 models, with some older Motorola
Astro digital SABRE models still being used by very few officers and some still inside older police vehicles. ROVERs are normally gun belt-mounted. For convenience, smaller, corded, hand-held speaker-microphones can be plugged into these radios and then clipped to parts of the uniform shirt such as a front pocket or shoulder loop. Originally, Motorola MX-series analog handheld units were used when the transition from VHF to UHF "T-band" dispatch/tactical frequencies was made in the early 1980s. Prior to that, portable 2-way radios (known in LAPD jargon then as "CC units") were either VHF or UHF, mainly Motorola HT-200s and HT-220s, stocked in small quantities, and used mainly by specialized units such as the
Metropolitan Division,
SWAT,
Special Investigation Section and Narcotics divisions as stakeout tools. Another use was for foot patrol units, mainly in Central Division, in the late 1970s and early 1980s.
Digital frequencies After the parade in Los Angeles celebrating the
Los Angeles Lakers 2001
NBA championship title, the LAPD switched from analog frequencies to digital frequencies. This ended a long-lasting era of the public having easy listening access to police broadcasts that started when the department had initially set up agreements with a local, commercial AM radio station to interrupt regularly scheduled programming for a crime broadcast. Officers were tuned to a specific radio station. However, as the amount of broadcasting needed increased, the department established its first transmission tower in Elysian Park and eventually began broadcasting over dozens of frequencies in the 400 MHz and 500 MHz ("T-band") ranges. These digital transmissions can be monitored on a proper Uniden Bearcat or Whistler digital scanner. The LAPD uses a variety of frequencies, grouped depending on usage. The following groups are worth mentioning: •
Dispatch channels; used for Dispatch ←→ Car communications of which there are 27, •
Fallback channels; used as backups incase of any major technical disruptions, of which there are 25, •
Bureau Tacticals; used for Car ←→ Car communications as well as the co-ordination of large scale situations inside a given bureau jurisdiction. There are two tacticals for each bureau - additionally, there are seven "Citywide Tacticals" used for citywide-scale situations. ==Rank hierarchy==