A 44-year-old has been arrested on suspicion of murder after a man was stabbed to death on his mobility scooter.
The man was arrested at an address in Southall, west London, in the early hours of Thursday and remains in custody, police said.
Thomas O’Halloran, 87, was attacked on a road in nearby Greenford on Tuesday afternoon.
Police believe he manged to travel about 70 metres on his scooter before flagging down a member of the public for help.
He was pronounced dead at the scene despite the efforts of police and paramedics to save him.
On Wednesday police released images of a man “fleeing the scene” in Cayton Road “armed with a knife”.
Mr O’Halloran was known for busking outside his local supermarket and Greenford station to raise money for charity, including for Ukraine.
Police described him as a “very well known” and “much-loved” member of the community.
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Thomas O’Halloran busks with friends
He was originally from Ennistymon, Co Clare, in the west of Ireland, and is said to have returned home regularly.
Detective Chief Inspector Jim Eastwood said: “I would like to thank the public for their overwhelming support following this horrific incident.
“As a result of the release of a CCTV image yesterday, an arrest has been made and this investigation is progressing at pace.
The victim’s scooter pictured in Cayton Road, Greenford
“Mr O’Halloran’s family have been updated with this development and continue to be supported by specially trained officers.
“I would reiterate their previous request that their privacy is respected by everyone as they continue to come to terms with their tragic loss.”
Met Police are asking anyone with video of the incident to upload it; detectives can also be contacted on 020 8358 0300; or information can be given anonymously via the Crimestoppers charity.