A FOURTH man has been arrested in connection with the murder of a 25-year-old man in Dollis Hill.
A 23-year-man was arrested on suspicion of murder at an address in Wembley on Monday.
He remains in custody pending further enquiries.
Three men aged 17, 17 and 31, were arrested on the night of the killing, Saturday May 19, and have been bailed to return pending further investigation.
Officers are continuing to appeal for witnesses and information after a murder in Dollis Hill.
Police were called to Coles Green Road at around 11.30pm on Saturday 19 May to reports of a stabbing.
Officers and London Ambulance Service attended the scene and two victims were found.
Luke Fitzpatrick, 25, who lived locally, died at the scene. A post-mortem held at Northwick Park Hospital on Sunday gave the cause of death as stab wounds.
The second man, Luke's father Bernard, aged 56, was taken by ambulance to a London hospital where his condition is understood to be serious but stable. He sustained injuries while reported trying to physically protect his son from the attack.
Both victims had been at The Ox and Gate pub in Coles Green Road, where people were gathered to watch the Champions League final on TV.
It appears that some sort of altercation began which spilled outside the pub, and a short distance away the victims were stabbed at Crest Road, at its junction with Alder Grove.
DCI Duffield said: "We urgently need to hear from anyone who was in or near the Ox and Gate pub around 23.30pm that evening.
"The pub was still very busy at that time, and we are confident that several people will have seen elements of what happened - we urge them to come forward and contact the incident room. If they wish to remain anonymous they may call Crimestoppers."
Any witnesses or anyone with information can call the incident room on 020 8358 0400. Anyone wanting to remain anonymous please call Crimestoppers on 0800 555 111.