Yes, after you complete a desk, you'll have a option to free roam, you can go find hidden vehicles, newspaper, films reels, landmarks.
By doing this, you'll have to go to the main menu, cases, and select what desk you want to complete all the street crimes.
All the street crimes that you haven't complete, it's on red on the map.
If you complete all the street crimes, at the beginning, it'd say "All the street crimes are completed on this desk".