I don’t know how it works in the UK, but if possible I’d look into getting a protection order against harassment. Definitely gather whatever evidence you can (a security camera might be a good investment), but with someone like this they may very well tell on themselves if it goes to court. A reasonable person wouldn’t be doing something like this in the first place, so they may well make it readily apparent that this is the sort of thing they think is acceptable in a court room. Especially if they’ve admitted to you to doing it on purpose.
If you’re able to request police body camera footage, it might be worth it to do that after calling in a noise complaint, and if you share a hallway you might be able to record the interaction yourself if not. If you rent and do share a hallway, consider asking your landlord to install a camera in a shared space so that you can get footage that way. Make sure to check the laws in your area regarding consent for recording. If you’re allowed to record secretly, maybe you can get them to admit it again on camera.
I had a similar situation to this with a transphobic neighbor who was doing this for about 6 months. A court date got it squared away, because she told on herself to the police while on our hallway camera. It might help in your situation too.
That’s a weird spelling of “hate-crime”.