How much power can a leaseholder have?

I have a tenant in my flat who is committing antisocial behaviour, playing loud music and has threatened to kill my other half because we asked him to turn the music down. The police are involved and we are trying to get environmental health involved but how much power does the leaseholder have to evict him?

I mean he lives in the flat above me, not in my flat.

The tenant is the leaseholder, usually. I assume you mean the landlord? Your syntax suggests you are in the UK. In any event, the landlord is going to have to bring a court action for eviction. It this is a council property, there are new laws that facilitate the eviction of antisocial tenants. How about an ASBO though: violations can be pursued through comtempt action; this can be very effective with neighbours from hell.

Your lease no doubt gives you the right of "quiet enjoyment" whether in the UK or the USA. You can pursue your landlord on that point.

The landlord or property management are there for one reason, and that is money. Send a letter certified to them with a copy of the police report and any other pertinent documents including your letter of your concern and moving notice. This should get their attention. If you want include a cc with the name of an attorney on it. Your written lease should ensure that you can enjoy your rental/flat and if the owner does not resolve the issue with your neighbor, you have the right to vacate.

I think the question you should be asking here is What are your rights?

You have a right to the quiet enjoyment of your property so an action in nuisance would be in order. Talk to a solicitor who specialises in tort.

Threats to kill are more serious. This is a police matter.

There will be clauses in the lease that prevent him from doing certain things and there will also be implied terms in the lease at common law.

One of which will probably cover nuisance.

I hope this helps

Good luck.

If this person owns the flat, then there is little prospect of being able to deal with him other than through the police and local authority. Making threats to kill is a criminal offence and the local authority can serve an abatement notice on him. Keep a careful note of all occurrences and persist in getting in contact with the noise officer in the local authority, so that he/she can come round and take decibel measurements.

You could consider civil proceedings in nuisance against the person concerned, but it would be very daunting to make an enemy of someone living above who obviously doesn't like you in the first place. As it is, complaining to the police and local authority will have stirred things up.

You might want to bring proceedings against your landlord for breach of covenant if he is allowing a fellow tenant to commit a nuisance against you. Even if there is not an express condition of quiet enjoyment in your lease, it is an implied term of any tenancy. Implied obligations of a landlord that a tenant's peaceful enjoyment of the premises shall not be interfered with by the landlord or by any person who claims under him (that is, the fellow upstairs). "Quiet" is not restricted to an absence of noise; it has been interpreted as "uninterrupted". The Tenant's remedies for breach of his/her quiet enjoyment are damages and injunction.
That is rather a drastic thing to do, but if the landlord is convinced that this man is behaving in a way which is a nuisance to other tenants he could bring forfeiture proceedings against him.