Flock Cameras in Douglas County
How they're used for good, the arguments against, and the future of community surveillance
Driving through the metro area, you may have noticed unfamiliar devices mounted on light poles at intersections. If you have wondered what they are, you are not alone — and the answer is worth knowing.
What Are License Plate Readers?
License plate readers (LPRs), also known as automated license plate readers (ALPRs), have been in use for roughly 50 years. They originated in the United Kingdom in 1976 as a tool to combat terrorism, but did not see widespread adoption until the 1990s and 2000s, when the cost of the technology dropped significantly. [1]
In casual conversation, people often call them “Flock cameras,” but Flock Safety is simply one brand among several. Other LPR providers include Leonardo/ELSAG, Insight LPR, and Axon.
Over the past couple of decades, law enforcement use of LPRs has increased. According to the Bureau of Justice Statistics’ 2020 Law Enforcement Management and Administrative Statitistics Survey, larger law enforcement offices were more likely to use LPR technology: nearly 90% of sheriff’s offices with 500 or more sworn deputies reported using the technology, and 100% of police departments serving > 1 million residents reported using LPRs. For comparison, Douglas County Sheriff’s Office has 638 full time equivalent officers.
LPRs in Douglas County
The Douglas County Sheriff’s office currently has 35 LPRs across unincorporated Douglas County, first installed in 2022. In addition, all municipalities within the county use them as well, adopted at varying times:
Lone Tree: 16 cameras, first installed in 2024
Parker: 11 cameras, initially installed in 2022
Castle Rock: 32 cameras, installed in 2021
Some law enforcement vehicles are also equipped with mobile LPR systems capable of alerting officers to nearby license plates associated with stolen vehicles, wanted persons, or other law enforcement notifications while on patrol or conducting proactive checks of business parking lots. Many of the area law enforcement agencies began using mobile LPRs before they installed stationary ones. For example, Castle Rock began using mobile LPRs as early as 2016.
What They Capture — and What They Don’t
LPRs photograph or video the rear license plates of vehicles as they drive past the camera.
They do not photograph or record the faces of drivers or passengers. They do not use facial recognition, or capture gender or race. The data collected include a license plate image or video, along with the date, time, and location of the vehicle when the photo was taken. The Flock Safety system clearly communicates on their website what data they capture via their Usage and Privacy Policy.
How They Work
When a vehicle drives past an LPR, the camera captures a photo of the license plate. That image is then automatically compared against a series of state and national databases, including:
NCIC — the National Crime Information Center
CCIC — the Colorado Crime Information Center
NCMEC — the National Center for Missing & Exploited Children (including AMBER and Silver Alerts)
These databases contain what are known as “hot lists” — records of license plates associated with vehicles of interest. If a captured plate matches one on a hot list, the LPR system sends a real-time alert to a law enforcement officer. Hot list matches can include:
Vehicles linked to stolen property
Active crimes or felony warrants
Missing persons (AMBER/Silver alerts)
Significant administrative violations, such as suspended registrations
Who Uses LPRs?
LPRs are primarily a law enforcement tool, placed by government entities on streets and roadways. But LPRs can also be a valuable tool for private entities: Park Meadows Mall has cameras on its property; homeowner associations in the metro area use them to monitor who accesses their communities.
When non-government organizations use LPRs, they typically set up agreements to automatically share their LPR data with law enforcement agencies so when there is a vehicle in the area that has a hit on the “hot list,” law enforcement can quickly act on this information based on the law enforcement agency’s policies.
How Law Enforcement Acts on the Data
A match on the hot list does not result in automatic action. The LPR system notifies an officer, who then decides how to respond based on the severity of the situation and available staffing.
Because the vehicle is moving when the plate is captured, officers cannot know exactly where it is by the time they respond. As one law enforcement official put it: they at least know which part of the haystack to search.
Crucially, even after a vehicle is located, officers must independently verify all relevant information before taking any action — confirming the vehicle type and model, checking its registration, and identifying who is in the vehicle. The LPR alert is a starting point, not a conclusion.
This process is similar to the familiar practice of an officer “running a plate” during a traffic stop. What LPRs do is automate that initial check and dramatically increase its speed. The same follow-up requirements still apply.
Other Law Enforcement Uses
Finding someone with an outstanding warrant is the most common use of LPR data, but the technology has also proven valuable in solving crimes after the fact.
In one notable local case, a shooting occurred at a retail establishment, and the suspect fled in a vehicle. Law enforcement requested a list from the LPR company of all vehicles captured in the area at the time of the incident. By cross-referencing that list with other evidence, investigators were able to identify and arrest the shooter. Law enforcement said it was highly unlikely they would have found the suspect without that data.
Colorado is in the top five states for vehicle thefts per 100,000 residents [Source]. LPRs improve the chances of locating a stolen vehicle that has been reported to law enforcement.
The Numbers
The scale of LPR activity is significant. According to Castle Rock’s public dashboard, in the 30 days leading up to May 14, 2026, the city recorded 806,001 unique plate reads. Of those, 11,485 resulted in a hot list match — about 1.4% of all reads.
According to a 2025 Denver7 article, the Douglas County Sheriff stated that LPRs had helped make at least 60 arrests in the county. In a public statement, Sheriff Weekly noted that the technology had helped catch suspects in cases involving robbery, murder, kidnapping, rape, and the identification of registered sex offenders near schools.
You can see where cameras are located by accessing various online databases. An example of one of these databases is deflock.org.
Some municipalities have pages on their websites to inform their communities about their LPR usage and policies. Here is an example from Castle Rock. We did not find similar pages for Parker, Lone Tree or Douglas County. Highlands Ranch does not have its own police force since it is unincorporated; the Douglas County Sheriff patrols Highlands Ranch.
What Are the Concerns?
The primary concerns against LPRs center on privacy violations, the potential for mass surveillance, and mission creep. Critics argue that logging every vehicle’s movement creates a trackable record of people’s lives with a warrant, raising constitutional concerns.
Mass Surveillance and the Fourth Amendment: Critics, including the American Civil Liberties Union, argue that deploying expansive networks of cameras creates a dragnet that tracks innocent, everyday citizens rather than just targeted suspects. This continuous tracking risks building a “mosaic” of personal habits, which critics claim violates reasonable expectations of privacy without judicial oversight.
Data Sharing and “Mission Creep”: Some law enforcement agencies share data with outside entities, based on their state or local laws. Privacy advocates argue this leads to mission creep - where data intended for investigating violent crimes or stolen vehicles is used by federal agencies for Immigration Enforcement, or by out-of-state jurisdictions for other civil or criminal offenses.
Security Risks: All centralized databases are vulnerable to data breaches and cyberattacks. A database that stores millions of plate scans and vehicle images is of significant concern for exposure.
Impacts to First Amendment Rights: The knowledge that someone’s activities are being recorded by the government can deter citizens from exercising their first amendment rights, such as participating in vehicle-based protests or visiting specific religious or political organizations.
Accuracy and Reliability: Some critics point to historical errors in license plate recognition that can lead to false “hits,” potentially causing unnecessary traffic stops.
Because of these concerns, according to the National Conference of State Legislatures, at least 16 states have statutes that expressly address the use of LPRs or the retention of data collected by LPRs.
Using and Regulating LPR Data
LPR companies own and control the data collected by their systems, carefully limiting who can access it. For example, while a business or HOA may host license plate readers on its property, it typically does not have direct access to the collected data. Instead, the data is only shared with law enforcement when a vehicle matches an entry in a law enforcement database.
Even without direct access, these systems can still provide value to businesses and HOAs by helping law enforcement quickly identify and locate vehicles or individuals in the area that might otherwise go undetected.
LPR companies typically retain data for 30 days, after which it is permanently deleted and cannot be retrieved, unless there is a specific reason to keep specific data as required by law enforcement or a court order.
In 2024, Colorado passed Colorado Revised Statute 24-72-113, which placed a limit on the retention of passive surveillance records used by a government entity. Passive surveillance records has a broad meaning in this statute, but is focused on recording devices positioned to capture moving or still pictures or images of human activity [emphasis added] on a routine basis or for security or other purposes. This statute limited access to one year after the creation of the passive surveillance record; it also allowed access up to three years if there has been a notice of a claim filed, an accident or other incident that may cause the record to become evidence in a proceeding.
Still, the concern is real enough that Colorado’s 2026 legislative session saw the introduction of Senate Bill 26-070, which aimed to regulate how LPR data is accessed and used by government agencies. The bill’s sponsor, Sen. Amabile of Boulder, framed it as a response to constituent demand: her constituents and others do not want to live in a society where their movements are constantly monitored and tracked.
The bill ultimately did not advance, largely due to strong opposition from law enforcement and a veto threat from the governor. Law enforcement’s core objection was a provision that would have required agencies to obtain a warrant before accessing LPR data older than 72 hours. The concern: to get a warrant, officers must already have probable cause — meaning they must already know enough to identify a suspect. In cases like the shooting described above, officers used LPR data precisely because they did not yet have a suspect. Additionally, not all crimes are discovered within a 72-hour window, which would have made older data effectively inaccessible in many investigations.
At the federal level, there is currently no specific legislative framework governing law enforcement use of LPRs, though existing laws and policies around law enforcement investigations do apply. [Source: https://www.congress.gov/crs-product/R48160]
In Colorado, it remains to be seen if state legislators will try again to regulate LPR data in the future.
Additional Resources:
Parker Police Department 2024 Annual Report: https://www.parkerpolice.org/DocumentCenter/View/24545/2024-Parker-Police-Department-Annual-Report?bidId=
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Well done! As long as the cameras record exactly what happened, and don't cut off after fifty seconds, I'm fine with them.
Informative article that strikes a balanced view of this subject--thank you. I would take issue with two issues--one said, one unsaid.
First, the statement: "homeowner associations in the metro area use them to monitor who accesses their communities." Having served on the Castle Rock Public Safety Commission for two years (Chair for one) and being on the Board of Directors for one of the biggest HOAs in Castle Rock for the last 7.5 years, which decided to install Flock Cameras at all ten of our entrances after a multi-year study process, this statement is misleading in the impression it creates. I know of no association that "monitors" or even has access to the data. The data is gathered and never accessed by anyone other than the Castle Rock Police Department, and only when needed to actively pursue or investigate a crime. They are valuable to decrease the size of the haystack to make it easier and faster to solve a crime or catch a criminal, AND obtain a conviction by having more localized proof of their location. But, HOAs have no access to nor play any active role in "monitoring who accesses their communities."
Second, the part unsaid is, perhaps, the biggest benefit Flock Cameras provide. In the "old days," a car would be stolen to be resold or chopped for parts. While that does still happen, cars are more commonly stolen to commit other crimes and decrease the chance of getting caught. So, apprehend someone who has stolen a car, and you are very likely to be apprehending someone who has committed other crimes in the past AND WILL COMMIT OTHER CRIMES IN THE FUTURE. Technological advances in law enforcement, like fingerprinting, forensics, and the utilization of portable radios and computers, all empowered LEOs to solve and respond to crimes more effectively. This technology, however, statistically allows them to effectively PREVENT future crimes--all while acting as a force multiplier that is much cheaper than hiring more officers to try to duplicate the monitoring power the network of cameras provides.
I think these distinctions are vitally important to recognize as the value proposition for using LPR cameras is a mixed bag of good and potential bad--just as any other tool. The cost-benefit analysis requires a nuanced understanding of how they operate.