Can local law enforcement make traffic stops in unmarked vehicles?

[louweed]

Jurisdiction

Illinois

Had a couple detectives (civilian clothes) in an unmarked city police vehicle pull me over for not having my front plate affixed to my vehicle. Turned out they wanted to talk to me about a possible criminal matter unrelated to the front plate not being on my vehicle. Fyi, the reason I ask is because I've been hearing that it is illegal (in certain states) for unmarked cars to pull over people for moving violations. Is it legal? How do I find out if it's legal for my state/local agency?

 

[army judge]

I suggest you contact the chief or desk sergeant of the agency that you claimed made the stop.

Once you make contact, ask the big boss, or the little boss.