Neighbour troubles?

Okay so someone has been spitting on my car, but now it's been keyed. We've had nails put in the garden (near the tyres), our old internet wire has been cut, luckily it was our old one, and we think it's the neighbour who has done it. They are in their 60s and a few days ago I walked out of my house and they were outside and they muttered something under their breath. We don't have any proof that the neighbour spat on the car or keyed it but it only started after the neighbour had a disagreement with my father. What should I do? It's stressing me out and I don't feel safe knowing someone is targeting my family. I'm waiting for the day a brick comes through the window or a fire gets set.

Ps the police haven't done anything, all they've done is phone us and talk to us and the neighbours family.