That's not a question you should ask on here imo.
Go down to the police station and explain it there. British police can be very ok, you'd have to be very unfortunate to get a dodgy one. There is no statute of limitations on certain charges but it all depends on evidence, do you have it or some? Otherwise it will your word against his word. Again ask the police.
I used to be quite well known among the local plod in a good manner. Not many people have the balls to tell five theiving pikey's caught in the act who started threatening me with ' don't you know who we are' to fuck right off.
Unlike my local inbred pedo wankers. I left a google review explaining the previous sentence in detail which they only got removed by the corrupt google employee's. I even called two corrupt chief of police commissioners corrupt pedo wankers and they haven't had the balls to charge me with slander to the police it's such a joke.
Even went to the cop shop to explain in person to them, without using threatening behaviour, that the next time they drive on to private property and I manage to catch them that people would read about it in the paper. They haven't had the balls to show their faces again and they're pretty dodge here.
They switch off the gps tracker in the van and then go around beating up gays at the gay dogging place lol.