Detectives investigating the 'violent and sustained' murder of a man found stabbed to death on a bus in Marylebone has been named.
The deceased has been formally identified as 48-year-old Archie Sheppard from Neasden .
Officers have established the victim was attacked on the upper deck of the bus just after midnight on Friday (April 28).
Detectives continue to appeal for witnesses and information to help piece together the events which led to Mr Sheppard's death.
Officers are keen to trace a man, described as a black male, who boarded the 189 bus from Brent Cross bus station with the victim at 11.13pm, and also sat on the upper deck, although not together.
Anyone who was in the area of Brent Cross bus station at around 11pm and any passengers that boarded the bus that left Brent Cross at 11.13pm are urged to get in touch with police.
Detective chief inspector Noel McHugh, of the Homicide and Major Crime Command, who is leading the murder investigation, thanked people who have already come forward with information to assist the investigation.
He said he is also aware there were more witnesses onboard the bus, on both the upper and lower decks, and would like to speak to them.
DCI Noel McHugh, said: "Despite the late hour, Brent Cross bus station is a busy terminus and there would have been a number of people around who would have seen Mr Sheppard waiting for the bus.
"Our enquiries so far have established that Mr Sheppard and the man we are seeking to trace were seen talking together while waiting at the bus station.
"They both boarded a route 189 bus and made their way to the upper deck where they sat separately.
"We are exploring the possibility that Mr Sheppard may have known his attacker and it is vital that anyone who saw the two men talking prior to boarding the bus contacts us.
"Approximately 40 minutes into the journey, Mr Sheppard was subjected to a violent and sustained attack.
"His attacker fled from the bus at Gloucester Place at the junction with Montagu Place heading in the direction of Marble Arch.
"Mr Sheppard was discovered when a passenger made their way to the upper deck and an ambulance was called. He was taken off the bus for urgent medical intervention but sadly died at the scene.
"It is crucial that we speak with all potential witnesses so I would urge anyone who has yet to speak to us to do so immediately."
Emergency services were called to reports of a man with stab wounds on the bus in Gloucester Place near the junction with Dorset Square just after midnight.
Mr Sheppard was pronounced dead at the scene.
A post-mortem is scheduled to take place at Westminster Mortuary today (Saturday April 29).
Anyone who witnessed the incident or the events leading up to the murder is urged to contact the incident room on 020 8785 8099 or via Twitter by using @MetCC.
To report information anonymously, visit Crimestoppers online or call on 0800 555 111.
No arrests have been made. Police enquiries continue.
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