Chicago Police Scanner: America's 3rd Largest City Goes Dark
Chicago has implemented one of the nation's most restrictive police radio policies—full encryption of CPD zones, 30-minute delayed official feeds, and a policy allowing sensitive transmissions to be redacted before release. Meanwhile, nearby Highland Park's open scanners helped save lives during a mass shooting. Here's the full picture of scanner access in the Chicago metro area.
Chicago Area at a Glance
Chicago represents one of the worst-case scenarios for police transparency. The Chicago Police Department encrypted its dispatch zones between 2021 and early 2023, and the Cook County Sheriff and Illinois State Police are encrypted on STARCOM21—cutting off nearly 10 million metro area residents from real-time law enforcement information. Chicago Fire's main dispatch, by contrast, remains in the clear.
The contrast with nearby Highland Park is stark: when a mass shooter attacked the July 4th parade in 2022, Highland Park's open police scanners helped civilians avoid danger zones, locate loved ones, and make life-saving decisions in real time. Chicago's encrypted system would have left them in the dark.
The Highland Park Lesson: When Open Scanners Saved Lives
Highland Park (Open)
Lake County, IL - July 4, 2022
- Real-time scanner access during active shooter
- Civilians knew which areas to avoid
- Families located separated loved ones
- Journalists provided accurate, immediate updates
- Reduced 911 overload from information-seekers
- Result: Lives saved through public awareness
Chicago (Encrypted)
Cook County, IL - Same Region
- 30-minute delay on all police communications
- Policy allows "sensitive" transmissions to be redacted
- Zero real-time awareness of police response
- Media dependent on official statements only
- Social media rumors fill information vacuum
- Result: Public left in the dark during emergencies
Read the full Highland Park case study: How Scanners Saved Lives →
Chicago Metro Agency Status
| Agency | Type | Status | Notes |
|---|---|---|---|
| Chicago Police Department | Police | Encrypted | Encrypted zone-by-zone 2021-2023; official feeds delayed 30 minutes, with sensitive transmissions subject to redaction |
| Chicago Fire Department | Fire | Open | Main fire and EMS dispatch remain in the clear (P25 digital); some tactical channels encrypted |
| Cook County Sheriff's Office | Sheriff | Encrypted | Dispatch on STARCOM21, listed ~99% encrypted in the RadioReference database |
| CTA (Chicago Transit Authority) | Transit | Partial | Rail operations audible via live feeds; transit policing handled by CPD, which is encrypted |
| Illinois State Police District Chicago | State | Encrypted | STARCOM21 system; law-enforcement talkgroups encrypted since 2022 |
| DuPage County Sheriff | Sheriff | Partial | Some tactical channels encrypted; main dispatch varies by municipality |
| Lake County Sheriff | Sheriff | Partial | Mixed status; Highland Park PD remained open |
| Will County Sheriff | Sheriff | Partial | Partial encryption; some municipalities open |
| Kane County Sheriff | Sheriff | Partial | Mixed encryption status across municipalities |
How Chicago's Encrypted System Works
30-Minute Mandatory Delay
Official police audio feeds are held for 30 minutes before public release. During active emergencies, this means the public hears nothing until long after events unfold.
Redaction Before Release
The city's policy allows transmissions it deems sensitive to be redacted from the delayed feeds before release—with no public log of what gets removed.
Media Opposition
A coalition of Chicago news organizations—including the Sun-Times, Tribune, and Chicago Public Media—formally opposed the delay policy, warning it "could put lives in jeopardy when mere seconds matter."
Zero Real-Time Access
No journalists, residents, or emergency managers can hear live police communications. For police activity, the public is dependent on official statements and delayed audio.
Beyond Chicago: Collar Counties & Suburbs
Cook County
Beyond Chicago proper, the Cook County Sheriff and many suburban police departments have followed Chicago's lead toward encryption on STARCOM21. Over 5 million residents affected.
Lake County
Mixed status. Highland Park maintained open communications—a decision that proved critical during the 2022 mass shooting. Other municipalities vary.
DuPage County
Partial encryption. Some tactical channels encrypted while main dispatch varies by municipality. Check RadioReference for specific department status.
Will County
Mixed encryption status. Some municipalities remain accessible while others have followed the encryption trend. Joliet and other cities vary.
Kane County
Partial encryption across municipalities. Aurora and Elgin have varying policies. Check current status before assuming access.
McHenry County
Further from Chicago, McHenry County has historically maintained more open access, though this continues to evolve.
Listening to Remaining Open Agencies
While Chicago and Cook County are encrypted, some collar county agencies remain accessible. Here's how to monitor what's still available.
Online Streaming
Broadcastify hosts feeds for some collar county agencies. Search for specific counties (Lake, DuPage, Will, Kane) to find active feeds.
Find online feeds →Digital Scanner
Illinois agencies use various P25 systems. You'll need a P25 Phase II capable scanner for most modern systems. Encrypted agencies cannot be monitored.
Scanner buying guide →Check Before You Buy
Before investing in scanner equipment, verify your target agencies are actually open. RadioReference.com maintains current encryption status.
Illinois on RadioReference →Technical Details
- Chicago Police: Encrypted digital zones - official feeds delayed 30 minutes
- Chicago Fire/EMS: Main dispatch in the clear - P25 digital (UHF)
- Cook County Sheriff: STARCOM21 P25 Phase II - ~99% encrypted
- Collar Counties: Various P25 systems - Status varies by agency
- State Police: STARCOM21 - Law-enforcement talkgroups encrypted
- Resource: RadioReference Illinois Database
When Encryption Creates New Problems
January 2026: Chicago Officer Charged for Selling Radio Access
Chicago Police Officer Alain Dillon was charged with taking $500 payments to let others use his encrypted police radio—3 counts of bribery and 15 counts of official misconduct.
Encryption was sold as a security measure. Instead, it created a monetizable asset for corrupt officers. The public can't access police communications—but if you pay enough, apparently you can.
See 23+ documented cases of insider corruption →Fight Back: Restore Transparency in Illinois
Chicago's encryption represents a policy choice, not a technical necessity. Communities across Illinois can push back—and point to Highland Park as proof that open communications save lives.
Contact Your Alderman
Chicago's City Council has oversight over police policies. Demand answers about why encryption was implemented without evidence of harm from open scanners.
File FOIA Requests
Ask for documentation of any incidents where scanner access caused harm. Other cities have found zero responsive records—Chicago likely has none either.
Point to Highland Park
The July 4th shooting is undeniable proof that open scanners serve public safety. Make officials explain why Chicago chose the opposite approach.
Support Collar County Transparency
If you're in DuPage, Lake, Will, or Kane counties, engage now before encryption spreads. Thank agencies that remain open.
Frequently Asked Questions
Is Chicago Police Department radio encrypted?
Yes. Chicago encrypted CPD radio zone-by-zone between 2021 and early 2023 as part of its digital migration. Public access is limited to official feeds delayed 30 minutes, and the city's policy allows transmissions it deems sensitive to be redacted before release. Real-time scanner access is blocked.
Can I listen to Chicago Fire Department on a scanner?
Yes, as of June 2026. Chicago Fire's main fire and EMS dispatch channels remain in the clear on digital P25, per the RadioReference database, and live feeds carry CFD audio. Some tactical and joint-operations channels are encrypted.
Is Cook County Sheriff encrypted?
Largely, yes. The Cook County Sheriff's Office dispatches on the STARCOM21 system, and its talkgroups are listed as roughly 99% encrypted in the RadioReference database. Cook County is the largest county in Illinois, covering over 5 million residents.
What about CTA and transit communications?
Mixed. CTA rail operations can still be heard on live scanner feeds. The CTA does not have its own police force—transit policing is handled by the Chicago Police Department, whose radio traffic is encrypted.
Are the Chicago collar counties (DuPage, Lake, Will, Kane) encrypted?
Status varies by municipality. The collar counties have mixed encryption policies—some agencies remain open while others have encrypted. Notably, Highland Park in Lake County maintained open communications, which proved critical during the July 4, 2022 mass shooting.
Why did Chicago encrypt when Highland Park stayed open?
City officials cited victim privacy, officer safety, and disruptive transmissions when they encrypted police radio during the 2021-2023 digital migration—a coalition of Chicago news organizations publicly opposed the delay policy. Highland Park maintained transparency, and during the 2022 July 4th shooting, open scanner access helped civilians avoid danger zones and locate loved ones.
What scanner do I need for Chicago area agencies?
You'll need a P25 Phase II capable scanner for Chicago Fire dispatch and the open collar-county agencies. CPD, Cook County Sheriff, and most major law enforcement are encrypted and cannot be monitored regardless of equipment. Check RadioReference for current status of specific suburban departments.
Is there any way to listen to Chicago police?
The only option is the city's official 30-minute delayed feeds on Broadcastify, and the city's policy allows sensitive transmissions to be redacted before release. There is no real-time public access—one of the most restrictive scanner policies among major US cities.