Searching for the impossible

[Lynnzer]

Now, this one is really way off topic but I'm buggered as to where else to ask the questions. I know there are a lot of very knowledgeable people on forum who may just have the answer to my quest.

So, here's the situation.
I and my immediate neighbours are having a great deal of trouble from a neighbour 50m further down the street. Around February this year I became aware of extremely bright security lights shining up from his house directly into my bedrooms at the front of the house. They were, and still are, comiing on frequently during the night with either one of them, or both of them activating without any seeming cause. The impact of them is that it is making sleep difficult as they really are that bright, almost like zenon car headlights. My neighbours are also affected and it has even been suggested that someone borrow a .22 air rifle.......

It's almost beyond belief but he has bloody big flags flying in his back yard underneath the lights and their motion detector cameras. Like I said: bloody stupid.

The householder is an agressive idiot who just tells you to F.O. and mind your own business, so asking him to do something about it is useless.

The council has been sent an official complaint and they have sent a letter telling him to do something about it. Of course that has been no use at all and the problem is ongoing. The council have now asked me to write a diary noting the dates, times, length of light being on etc so they can look into legal action, BUT that's damn stupid. I can't possibly keep watch all night long for a week to take notes. So I have decided the best way to do this is by using a webcam left running all night to record the incidents.

That throws up another problem though. I would need to use a programme to look at the recordings and flag each lighting incident so that the council can easily zone in to see them. The only way I can do this is to run the entire video capture and mark each incident, but of course that entails many hours sat at the computer.

So, here's the question. Is there a programme out there that can compare the running video and automatically mark in a flag for any sudden change of light, similar to Movavi which I already use, detecting a change of scene perhaps?

The street is extremely quiet at night with little other movement or light intrusion and is also pretty dark. There should no external influences on scene changes except for the sudden explosion of these security lights.

Any help would be appreciated