Police had a red light pointed at me on a residential road? Not sure what it is?

I was on a residential road last night around 11:30pm, there was an event that just happened in a park in that area and there were lots of police vehicles controlling the crowds exiting the park. Loads of traffic in all directions. I went into this residential road where I used to live which has speed bumps. I saw a big police van at the end of the road on the left side facing me. One lady was sat behind the van on the pavement next to two drunk girls, the other was a policeman stood next to the drivers door and stood up facing me with a red light pointing at me.

As the road has speed bumps, I was maybe doing 15-25mph max before slowing down for the speed bumps? Not sure what it was but I’ve never seen them on this road ever, and it’s unusual for them to be speed checking (if it’s a speed gun or speed detector device) at that time at night, and in an area where an event has just finished and people are exiting the area with loads of traffic on the main road. This road was the road off the main road for residents only and I was the only car coming down at the time.

What could it have been? Only saw it for a split second, it wasn’t his body cam, but looked like a little device pointing at me but really not sure what it is?