Ever been watching a cop show and heard something like “10-4” over the radio? Or maybe you’ve overheard “Code 3” during a police scanner broadcast? These mysterious numerical phrases aren’t secret police slang – they’re part of a structured communication system that helps officers relay information quickly and clearly.
Police codes, also known as ten-codes or police radio codes, have been an essential part of law enforcement communication for decades. Let’s dive into this fascinating world of numbers and their meanings that help keep our communities safe.
The Origin of Police Codes
Back in the 1930s, police radio communication was a new technology with significant limitations. Radio time was precious, channels were crowded, and messages needed to be concise.
Illinois State Police Director Charles Hopper recognized these challenges and developed the first standardized code system in 1937. His “ten-code” system (where messages begin with “10”) was designed to make radio communication faster and more efficient.
The Association of Public-Safety Communications Officials (APCO) later expanded these codes, creating what many departments still use today. Instead of saying “I acknowledge your message,” an officer could simply respond with “10-4” – saving valuable seconds that might make all the difference in an emergency.
Common Ten-Codes You Might Recognize
Even if you’re not in law enforcement, you’ve probably heard some of these codes in movies, TV shows, or perhaps from overhearing actual police communications:
- 10-4: Message received/understood (probably the most famous code)
- 10-20: Location/position (“What’s your 10-20?” means “Where are you?”)
- 10-8: In service/available
- 10-7: Out of service/unavailable
- 10-27: Driver’s license check
- 10-28: Vehicle registration check
- 10-32: Person with a gun
- 10-33: Emergency/officer needs help immediately
- 10-99: Wanted/stolen record
When you hear “10-4, good buddy” in movies, you’re witnessing the crossover of these codes into popular culture. The “good buddy” part actually comes from CB radio lingo used by truckers, showing how these communication codes have permeated different aspects of American culture.
Code Systems Vary By Region
Here’s something interesting – despite efforts to standardize these codes nationally, there’s no universal police code system used across the United States. Different departments and regions use different code systems, sometimes with completely different meanings for the same numbers.
For example:
- In some departments, “Code 3” means respond with lights and sirens
- In others, the same emergency response might be “Code 1” or “10-39“
- Some departments use three-digit codes (like “211” for robbery in California)
- Others use color codes (like “Code Blue” for a medical emergency)
This regional variation became particularly problematic during multi-jurisdictional responses to major disasters like Hurricane Katrina and the 9/11 terrorist attacks. When agencies from different regions tried to coordinate, their different code systems sometimes created confusion rather than clarity.
The Plain Language Movement
Following communication challenges during major disasters, there’s been a growing movement to replace codes with “plain language” communications.
The Department of Homeland Security and FEMA now recommend that emergency responders use clear, plain English rather than codes during multi-agency responses. Their reasoning is straightforward: “In an emergency, clear communication saves lives.“
Many departments now use a hybrid approach:
- Plain language for multi-agency operations
- Codes for routine, internal department communications
- Plain language for sensitive information that shouldn’t be obscured
When you hear an officer say “We have a person with a firearm at Main and Broadway” instead of “10-32 at Main and Broadway,” you’re witnessing this shift toward plain language communications.
Beyond Ten-Codes: Other Police Communication Systems
Ten-codes are just one part of police communication systems. Officers also use:
Signal Codes
Often used for situations or statuses:
- Signal 7: Dead body
- Signal 13: Officer needs assistance
- Signal 100: In pursuit
Phonetic Alphabets
When officers need to spell out something clearly over the radio (like a license plate), they use phonetic alphabets:
- A = Alpha
- B = Bravo
- C = Charlie
So “ABC123” would be communicated as “Alpha-Bravo-Charlie-One-Two-Three” to avoid confusion between similar-sounding letters like B, D, and V.
Color Codes
Some departments use color codes for specific situations:
- Code Red: Armed suspect
- Code Blue: Medical emergency
- Code Black: Bomb threat
Police Codes in Popular Culture
Police codes have infiltrated popular culture in fascinating ways. Shows like “Adam-12” and “CHiPs” familiarized viewers with police radio jargon in the 1970s and 80s. More recently, games like Grand Theft Auto incorporate police codes into their gameplay for authenticity.
The phrase “187” (California’s penal code for homicide) has made its way into rap lyrics and slang. Similarly, “5-0” (originally Hawaii Five-O, a TV show) has become slang for police presence.
Why Codes Matter
Despite the move toward plain language in some situations, coded communication systems continue to serve important purposes:
- Efficiency: Codes allow for faster communication when seconds count
- Clarity: Standardized messages reduce misunderstandings
- Officer safety: Codes can obscure sensitive information from civilian listeners
- Emotional distance: Using codes can help officers maintain professional detachment when discussing traumatic situations
As one veteran officer put it: “When you’re in a high-stress situation, codes become second nature. You don’t think about them – they just come out automatically, which lets you focus on your safety and the situation at hand.“
The Future of Police Codes
As technology evolves, so too will police communication systems. Digital communication, text-based systems, and encrypted networks are changing how officers share information. However, the fundamental need for clear, concise communication remains.
Whether departments continue using traditional codes, shift entirely to plain language, or develop new systems altogether, the goal remains the same: ensuring that critical information flows quickly and accurately between officers and dispatchers.
The next time you hear “10-4” in a movie or on TV, you’ll have a deeper appreciation for these small but significant parts of law enforcement history and practice – codes that have helped officers protect communities for nearly a century.