Can an unmarked patrol car pull you over in IL? What state policy and law allows
Most Illinois drivers likely know you need to pull over when a police officer initiates a traffic stop, but what if the car is unmarked?
Regulations on unmarked law enforcement vehicles vary by state. In Missouri, officers are allowed to pull people over in an unmarked vehicle if they turn on red or blue flashing lights or a siren.
While some states may allow police to make traffic stops in unmarked vehicles, there have been reports in the U.S. of people disingenuously posing as officers and making illegitimate stops. So what should you do if an unmarked car flashes lights or a siren at you, indicating you should pull over?
Here’s what to know about being pulled over by an unmarked police vehicle in Illinois.
Can unmarked police cars pull over Illinois drivers?
According to an attorney in Illinois, as well as the Illinois State Police, unmarked cars can lawfully pull over a motorist.
“Unmarked police cars can pull people over,” Illinois Legal Aid Online Deputy Director Gwen Daniels said in a July 2 interview with the News-Democrat.
An unmarked police car may have portable emergency warning lights, Daniels continued, which differ from the typical marked police cars, as well as semi-marked vehicles, which may have lights mounted within the car but don’t have the paint scheme of a traditional cruiser.
There are some limits on enforcement activity by unmarked cars.
“Unmarked police cars, however, cannot initiate a pursuit without supervisor approval,” Daniels said.
Illinois State Police pursuit policy does make an exception for unmarked police cars to initiate a pursuit without prior authorization when “there is an imminent threat to life or great bodily harm represented by the continued freedom of the suspect.”
Illinois State Police Trooper Josh Robinson also confirmed to the BND that unmarked police cars can lawfully make a traffic stop.
“An unmarked police vehicle will have both red and blue emergency lighting, although it may not be visible on the exterior of the vehicle until activated,” Robinson wrote in a July 8 email. “The officer, even undercover, will have visible markings or identification showing they are law enforcement. The officer will also show proper identification when asked. Drivers can also call 911 or a dispatch business line and verify the traffic stop is legitimate and they are being pulled over by a lawful officer.”
Robinson said officers driving unmarked police vehicles may sometimes be in uniform, but not always.
“Officers may be in other attire appropriate for their job function, but they will always display visible markings or identification for the department they represent and can provide identification upon request,” Robinson said.
Illinois drivers who are pulled over by an unmarked police car should follow the same best practices recommended when being pulled over by a marked police vehicle, Robinson continued:
Pull to the right side of the roadway.
Pull into a nearby parking lot or business off the roadway, if available.
Stay in your vehicle and wait for the officer to approach you. Do not reach for any documents or anything else within the vehicle until asked to do so by the officer.
If you are not sure it is a legitimate officer, you can turn on your four-way flashers and slowly proceed to a business where you feel more comfortable. You should also call 911 to verify the traffic stop is legitimate and to explain your reason for continuing with your four-way flashers on, Robinson said.
Belleville Police Department policy allows officers to initiate pursuits in semi-marked vehicles when justified, but there are limitations.
“Semi-marked units may initiate a pursuit providing the proper justification exists, but will relinquish Primary Unit status immediately upon the participation of a marked police car. Upon relinquishing Primary Unit status, semi-marked units shall terminate active involvement in a pursuit unless they are needed to fulfill Secondary Unit responsibilities or are otherwise directed by a supervisor,” BPD officials wrote in a response to a records request from the BND.
The department describes semi-marked vehicles as not identifiably marked by a distinctive color scheme. The vehicles could have red and/or blue lights mounted within the vehicle, can be equipped with siren and could have partial police marking. Like other unmarked police vehicles, an unmarked BPD vehicle has no identifying markings but may have portable emergency lights.
Additionally, the local department’s policy says except for use by the assigned member, “unmarked units shall not be used without first obtaining approval from the supervisor of the unit to which the vehicle is assigned.”
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This story was originally published July 11, 2025 at 5:00 AM.
