Police code 10-79 most often means bomb threat. When a dispatcher transmits it, officers move to establish a perimeter, begin evacuations, and bring in bomb disposal specialists. The code is not universal, though. A smaller number of agencies use 10-79 to mean “notify the coroner,” and others assign it to a major-injury traffic accident. The meaning depends entirely on which department is broadcasting it.
What 10-79 Means in Most Departments
In the majority of police agencies that still use 10-codes, 10-79 is shorthand for a bomb threat or a bomb-related emergency. Hearing the code tells a dispatcher to alert specialized units, start coordinating evacuations, and prepare for a potentially life-threatening situation involving an explosive device. Some agencies distinguish between a called-in warning and an actual suspicious device located on scene, but the initial code is typically the same.
The alternative uses are real and worth knowing about. In Wayne County, Indiana, 10-79 means “contact coroner,” and bomb threats fall under a different code entirely. Elsewhere, 10-79 is assigned to severe traffic collisions involving major injuries. If you hear the code on a scanner or see it in a report, the only reliable way to know what it means is to check the broadcasting agency’s own code list.
Why the Code Varies by Agency
The 10-code system was never fully standardized. The Association of Public-Safety Communications Officials proposed a shared list in 1935 and developed an initial version between 1937 and 1940, but as thousands of agencies adopted the system, each one adapted it to local needs. A coastal department needed codes for maritime emergencies that an inland agency would never use, so each filled the gaps differently.
The result is a patchwork. A few codes crossed into popular culture and are recognized almost everywhere, like 10-4 for “acknowledged” and 10-20 for “what’s your location?” Past those, consistency drops off quickly. 10-79 is a clean example: bomb threat in one county, notify the coroner in the next. Some departments also keep their full code lists confidential so suspects monitoring radio traffic can’t follow along, which further prevents any true national standard from emerging.
How Officers Respond to a Bomb Threat Call
Whatever code announces it, the response to a bomb threat follows a familiar pattern. The first officers on scene gather information from whoever received the threat: Was it a phone call, a written note, or an email? Did the caller name a location for the device or a detonation time? Those details drive every decision that follows.
Establishing a safety perimeter comes early. Officers are trained not to touch or move any suspicious item and to keep portable radios and cell phones away from the immediate area, because some devices can be triggered by radio signals. The Department of Homeland Security publishes recommended standoff distances based on the size of the suspected threat:
- Pipe bomb (5 lbs): mandatory evacuation of at least 70 feet, preferred distance of 1,200 feet or more
- Briefcase or suitcase (50 lbs): mandatory evacuation of at least 150 feet, preferred distance of 1,850 feet
- Car bomb (500 lbs): mandatory evacuation of at least 320 feet, preferred distance of 1,900 feet
- SUV or van (1,000 lbs): mandatory evacuation of at least 400 feet, preferred distance of 2,400 feet
- Semi-trailer (60,000 lbs): mandatory evacuation of at least 1,570 feet, preferred distance of 9,300 feet
Those distances are larger than most people expect. A car bomb’s preferred evacuation zone stretches over a third of a mile. Between the mandatory and preferred distances, anyone who cannot evacuate should shelter inside a building, away from windows and exterior walls.1FBIIC. DHS-DOJ Bomb Threat Stand-off Card
Hearing 10-79 on a Scanner
Most civilians who encounter 10-79 do so through a police scanner or a scanner app. Federal law generally allows this. Under 18 U.S.C. ยง 2511(2)(g)(ii), it is not unlawful to intercept a radio communication transmitted by a government, law enforcement, civil defense, or public safety system that is “readily accessible to the general public.”2Office of the Law Revision Counsel. 18 US Code 2511 – Interception and Disclosure of Wire, Oral, or Electronic Communications Prohibited If the signal is unencrypted and you can pick it up with ordinary equipment, listening is legal under federal law.
A handful of states add restrictions on mobile use. Florida, Indiana, Kentucky, Minnesota, and New York either prohibit or require permits for operating a scanner inside a vehicle, usually with exemptions for licensed amateur radio operators and credentialed press. Using scanner information to commit or evade a crime is illegal everywhere, regardless of whether the listening itself was lawful.
Encryption Is Changing What You Can Hear
Even where scanning is legal, more agencies are encrypting their radio traffic. Digital radio systems let departments scramble transmissions so only authorized receivers can decode them. Agencies cite two reasons: preventing suspects from tracking police movements in real time, and protecting the personal information officers routinely share on the air, like names, addresses, and ID numbers.
Some departments split the difference, leaving dispatch channels open and encrypting tactical or investigative channels. Others encrypt everything. The trend has accelerated since 2020, and the practical effect is that hearing a raw 10-code on a scanner is becoming less common each year.
The Shift Toward Plain Language
The same inconsistency that makes 10-79 confusing to the public is dangerous for first responders. When multiple agencies converge on a major incident, officers from different departments can use the same code to mean different things. In December 2006, the National Incident Management System issued an alert requiring plain language for any multi-agency, multi-jurisdiction event. Starting in fiscal year 2006, federal preparedness grant funding became contingent on using plain language during incidents that require cross-jurisdictional cooperation.3Cybersecurity and Infrastructure Security Agency. Plain Language Guide Frequently Asked Questions
The 2008 National Emergency Communications Plan went further, calling for “national adoption of plain language practices” and setting milestones for states to eliminate coded substitutions throughout the Incident Command System.3Cybersecurity and Infrastructure Security Agency. Plain Language Guide Frequently Asked Questions
Many agencies still use 10-codes for internal daily operations. The federal mandate applies specifically to multi-agency incidents, and officers who have spent entire careers thinking in code are slow to switch. For now, 10-79 is still in active use. Just confirm which agency said it before you assume what it means.