Like it'd be one thing if squad cars had seen heavy vandalism, sirens were damaged across the board, they can't get new ones shipped in/repaired units so they're using the closest damn thing that makes a loud noise.
They can't exactly borrow from ambulances and fire trucks because each of those is specifically designed to not interfere with each other to make it possible for uninvolved people to know where they are coming from in acoustically complicated areas, and I wouldn't be surprised if the demand for new units weren't that elastic.
Then again, you'd think there would be international suppliers to buy from. Though I could totally understand if only the French had extra stock. Better to sound like an Ice Cream truck than a French Police car. (Sorry guys, I just can't stand that sound).
If it is intentionally being done as some sort of psychological warfare tactic. What in the hell is with reaching back so far for a reference? Short of stumbling across this article in particular, or having a Gran around with primary insight of the time... It just seems like a stretch to me that a whole precinct of cops would be huddled together plotting to unleash an entire police force's worth of Ice Cream Truck siren equipped psychological warfare mobiles intended to strike fear into the hearts of 19th century black folk.
Then again, maybe there's a lot of history majors on the force? Bloody world is gone mad, and I'm not certain anyone is worth taking seriously anymore.
EDIT: I quit. I just can't even reasonably process the simultaneous horror /absurdity factor with this. Absolute madness.