Denver Police Encryption: When the Mile High City Went Dark
In 2022, Denver Police Department completed full encryption of all radio communications, joining a rolling regional blackout across Colorado's Front Range. The move came months after the Marshall Fire exposed how badly residents need real-time emergency information, and at a time when parents in the metro were leaning on scanner access during school lockdowns. Denver chose opacity anyway.
What Front Range listeners can still monitor
Denver, Aurora, Lakewood, CSP—all gone, and HB21-1250's media access framework has been paper-thin in practice. But federal, DEN airport aviation, Boulder and Fort Collins dispatch, wildfire air ops, and NOAA weather all remain in the clear across the Front Range. This is the stack Coloradans are actually using.
What Happened in Denver
Denver Police Department had operated with open radio communications for decades. Local news stations monitored police channels around the clock. Parents kept scanners during school emergencies. Neighborhood watch groups tracked nearby incidents. Amateur radio enthusiasts and scanner hobbyists formed an informal public safety network.
In 2022, that ended. Denver PD switched to P25 AES-256 encryption, making all police radio traffic inaccessible to anyone without department-issued equipment. Aurora, Lakewood, Westminster, and other suburban departments followed within months, creating a coordinated regional blackout.
The decision came despite Colorado passing HB21-1250 in 2021—the nation's first statewide law requiring agencies with encrypted systems to create media access policies. The law was meant to preserve transparency. Instead, Denver and its neighbors implemented encryption anyway, with media access policies that exist largely on paper.
The numbers
The Denver metro area, home to nearly 3 million people, went from open police communications to near-total secrecy in under two years.
The Marshall Fire: When Information Mattered Most
On December 30, 2021, the Marshall Fire tore through Boulder County, becoming Colorado's most destructive wildfire on record. Wind gusts up to 100 mph pushed flames across grasslands into suburban neighborhoods. Over 1,000 homes burned. More than 35,000 people evacuated, many with only minutes of warning.
Residents scrambled for information as official channels were overwhelmed. Evacuation zone boundaries shifted rapidly. Families who had been separated in the confusion had nowhere to turn for updates.
"We had no idea if our neighborhood was evacuating or not. The official app was delayed, CodeRed texts came late. If police radio had been accessible, we could have known what was happening in real time."— Louisville resident, December 2021
The Marshall Fire primarily hit Boulder County, where some agencies were still unencrypted. But it exposed the coordination problems that arise when encrypted and unencrypted agencies work together on mutual aid. Journalists covering the fire could not monitor Denver-area resources being deployed.
Denver pushed forward with encryption anyway, completing its transition months after the fire.
School lockdowns: parents without information
For years, Denver parents dealing with a school emergency had one practical option: turn on the scanner. During lockdowns they could follow what police were doing, hear whether a threat was contained, and decide whether to drive toward the school or stay away.
That ended in 2022. During a lockdown now, parents in the Denver metro face a specific set of problems:
- No way to know what police are doing or saying on the scene
- School notification systems routinely lag behind events
- Rumors spread in the absence of verified information
- Parents calling emergency lines for updates tie up dispatcher attention
- No way to make an informed decision about whether to drive to the school
The Highland Park shooting showed what open scanner access means during an active threat. Denver cut that off.
Impact on Local Journalism
Denver's local stations, KUSA 9News, KCNC CBS4, KDVR Fox31 among them, built their breaking news operations on scanner monitoring. Reporters dispatched within minutes of an incident. Photographers positioned themselves based on what they heard. Newsrooms could check police accounts against what was actually on the radio.
Before 2022, crime patterns across the city were visible to anyone listening. An independent record of police communications existed outside of what the department chose to announce. Since encryption, Denver news outlets depend entirely on what police choose to release. Significant incidents can go unreported for hours.
HB21-1250 was supposed to protect press access. As of 2026, no major Denver news organization has functional real-time access to police radio, despite the law's requirements.
The Unencrypted Comparison: Boulder, Fort Collins, and Beyond
While Denver went dark, several Colorado communities maintained transparency. The contrast is instructive:
| City | Population | Scanner Status | Documented Problems from Transparency |
|---|---|---|---|
| Boulder | 105,000 | Open | None documented |
| Fort Collins | 170,000 | Open | None documented |
| Greeley | 110,000 | Open | None documented |
| Denver | 715,000 | Encrypted | N/A - Chose secrecy anyway |
| Aurora | 390,000 | Encrypted | N/A - Chose secrecy anyway |
Boulder has kept communications open for decades with no documented harm. Fort Collins, a university city of 170,000, does the same. Neither department has produced evidence that open radio damaged officer safety or compromised investigations.
Denver's decision to encrypt was not driven by documented harm from open radio. It was an administrative choice to restrict public access.
What Denver Lost
The real-world consequences of going dark
Emergency awareness
During wildfires, severe weather, and active threats, residents have no direct line to police communications. Official notification systems consistently lag behind events on the ground.
School lockdowns
Parents whose children attend Denver-area schools can no longer monitor police response during a lockdown. There is no way to know what is actually happening at the scene.
Press independence
Denver newsrooms now depend on police to learn about police activity. There is no independent check on what the department chooses to announce.
Accountability
No public record of radio communications means misconduct is harder to surface. Residents have one fewer tool for monitoring how the department operates.
Colorado's Failed Promise: HB21-1250
In 2021, Colorado passed HB21-1250, the first statewide law requiring police departments with encrypted radio to establish media access policies. Journalists, civil liberties groups, and transparency advocates pushed hard for the bill.
The law requires:
- Written policies for credentialed media access to encrypted communications
- A process for journalists to apply for access
- Reasonable timeframes for reviewing applications
The result has been paperwork, not access. Agencies created policies, but actual access agreements are rare. Journalists report bureaucratic delays and no clear path to approval. The law has no meaningful enforcement mechanism.
Denver encrypted knowing HB21-1250 existed. The department wrote a media access policy that has produced no working access for any major news organization.
What You Can Do
Denver metro encryption is in place, but the policy is not settled:
- Contact your city council and push police departments to actually implement media access under HB21-1250, not just write a policy document
- Support local news organizations, which need resources to pursue access agreements and legal challenges
- Attend public meetings and raise transparency concerns when police budgets come up
- If you were harmed by the lack of real-time information during an emergency, write it down and share it with elected officials and advocacy groups
- Boulder, Fort Collins, and Greeley are still accessible. Tell those city officials you value that choice
- HB21-1250 lacks enforcement teeth. Advocate for amendments with real penalties for non-compliance
Take Action for Transparency
Your voice matters. Here are concrete ways to advocate for open police communications in your community.
Contact Your Representatives
Use our templates to email your local officials about police radio encryption policies.
Get StartedRead Case Studies
See how encryption has affected real communities - from Highland Park to Chicago.
View CasesSpread Awareness
Share evidence about police radio encryption with your network and community.
Public Testimony
Learn how to speak effectively at city council and public safety meetings.
Prepare to SpeakFrequently Asked Questions
When did Denver Police encrypt their radio communications?
Denver Police Department completed full encryption of all radio channels in 2022. Aurora, Lakewood, and surrounding agencies followed through 2022-2023, producing a coordinated regional blackout across the Front Range.
How did encryption affect communication during the Marshall Fire?
The December 2021 Marshall Fire destroyed over 1,000 homes in Boulder County. Residents reported confusion about evacuation zones and could not monitor updates in real time. While Denver proper was not directly in the fire's path, the regional encryption trend complicated mutual aid coordination between encrypted and unencrypted agencies.
Can parents monitor police channels during school lockdowns in Denver?
No. Since Denver Police encrypted in 2022, parents cannot monitor police response during school lockdowns. Families who previously used scanners to follow developing situations at their children's schools no longer have that option.
Did Colorado's media access law (HB21-1250) restore scanner access?
Colorado passed HB21-1250 in 2021, requiring agencies with encrypted systems to create media access policies. Implementation has been uneven. As of 2026, few news organizations have functional real-time access agreements with Denver-area law enforcement.
Are any Denver-area agencies still unencrypted?
Very few remain fully open. Jefferson County Sheriff and Douglas County Sheriff maintain partial encryption with some channels accessible. Most municipal police departments and the Colorado State Patrol are fully encrypted. Check RadioReference for current status of specific agencies.
Sources & further reading
- Colorado General Assembly: HB21-1250 text and legislative history
- Denver Post coverage of Marshall Fire communications
- Colorado Press Association encryption access reports
- Denver City Council public meeting records
- RadioReference.com Denver metro system documentation