Q&A - Using a Dashcam to Report Traffic Violators
If I have a dashcam and capture traffic violations and reported them, is it of any use for police to prosecute? If so does it depend on the level severity? What steps or how much involvement would be required of me? eg. appear in court, just sending a video etc.

Three swings and three strikes, figuratively speaking. This describes my experience making driving complaints to the police. In each case it appears that there was little interest in following up. In fact, one of the complaints was initially refused by the civilian complaint taker.