A man was found dead and a woman critically injured on Wednesday at an address on Northumberland Park Road in Tottenham.
The man, in his mid-30s, was pronounced dead at the scene.
The woman, also in her 30s, remains in hospital in a critical but stable condition.
The Met opened a murder inquiry on Wednesday. On Thursday, the force said they were not looking for other suspects in connection with the incident.
The pair are yet to be identified.
A regular at the pub, close to Tottenham's White Hart Lane ground, said it only opens on match days.
Another man, who did not want to be named, said: "We are all really shocked. It is a community pub."
Police have said they are not looking for anyone else in connection with the murder of a man at a flat above a pub in north London.