I am giving you a great big ole 9( I dont give 10's no one is perfect!), because I LOVE photojournalism and it just never seems to do well against all the contrived studio shots here..
And it is a great shot, tells a story, nice DOF and compostition, and enough blue, literally and figuratively to fit the challenge.
Man, I'm kind of torn. As stated in your title, this clearly is not "artistic photography"; it's "photo-journalistic." As such, it's a good shot (well-composed, clear, interesting, etc.). Also, it accomplishes the task of the challenge ("boys in blue" [cops], guy in a blue shirt, blue streaks of police car). I can't give it a "10," because I can't fight my predilection for looking for "artfulness," but I have to say that it's a great shot "of its kind."
Great candid. I was about to try to capture a police situation a few weeks ago where a cop was removing a homeless man from the sidewalk but I chickened out. I like the rain on the hood of the car too. 8