Tributes have been paid to the Irishman Thomas O’Halloran who was attacked with a knife while on a mobility scooter in west London on Tuesday.
London's Metropolitan Police said the Clare man was slain in a “shocking act” of “unprovoked violence”.
The 87-year-old died after being attacked in the Greenford area of the British capital.
Police said a “dangerous” knife-wielding man was seen fleeing the scene and was caught on CCTV.
In the early hours of Thursday, a 44-year-old man was arrested on suspicion of the murder of Mr O'Halloran.
He was arrested at an address in Southall, west London, police said.
Mr O’Halloran, who lived in Greenford, was originally from Ennistymon, Co Clare.
He is survived by his family, including his sister, two brothers, nieces and nephews.
'Heart of the community'
“We’ve lost the heart of our community”, former Labour MP for Ealing North Stephen Pound has said of the violent death of the Clare native.
Mr Pound told RTÉ radio’s Morning Ireland that Mr O’Halloran had always been looking for ways to raise money for people in need and had been collecting for Ukraine when he was killed.
“I don’t know why we called him Terry. I didn’t know much about his past. He was an absolute character and played up the cheerful Irishman stereotype.
“He was a sweet and lovely man.”
Mr Pound described Mr O’Halloran as “the uncrowned king of Greenford.” The former MP recalled that the Ennistymon-born Mr O’Halloran had frequently pointed him in the direction of people in need of help.
“He will be sadly missed.” While Mr O’Halloran may have been 87 years of age “in body”, he had a twinkle in his eyes of a 22-year-old and was very sharp.
“He was the cement that held this community together.”
Mr Pound predicted that Mr O’Halloran’s funeral would be “massive” as the community had lost someone who was considered “irreplaceable”. He was “a one-off, he was special,” he said.
Mr Pound said for the stabbing to have taken place at 4pm, in broad daylight beside one of the main roads in London had stunned the community.
Footage of Mr O'Halloran shows him busking to raise money for Ukraine months before the killing.
He can be seen playing his accordion and smiling with a makeshift blue and yellow collection box strapped to his frame in the video posted online in June.
Sporting a cap and glasses, he finishes his performance before breaking into a grin when a spectator remarks: “Lovely.”
'Deep shock and sadness'
Local Fine Gael senator Martin Conway said Mr O’Halloran visited Ireland regularly and that his death has left his home community in Ennistymon and north Clare in “deep shock and sadness”.
Mr Conway described it as “almost unbelievable” that an elderly man using a mobility scooter was targeted in daylight.
“It is truly shocking,” he said.
“I sincerely hope the perpetrators are brought to justice as soon as possible.”
“Tommy, as he was known, left Ennistymon for London 71 years ago but travelled home almost every year until about 10 years ago.
“He was a very popular man in the Greenford area of London, where he regularly played music and often busked for charity. Most recently, he raised money for the Ukrainian community living in London.
“I would like to offer my deepest sympathies to the O’Halloran family both in London and Ennistymon at this very difficult time for them.”
Local councillor Fianna Fail Shane Talty offered his sympathies to the Ennistymon community and Mr O’Halloran’s family.
Mr Talty said Mr O’Halloran left Clare as a young man but remained in contact with family there.
“Terribly sad way to see a long life brought to an end,” he said.
Detective Chief Inspector Jim Eastwood, who leads the investigation, 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.
“Mr O’Halloran’s family have been updated with this development and continue to be supported by specially trained officers.”
Detectives believe Mr O’Halloran was stabbed in Western Avenue about 4pm before managing to travel 75 yards or so on his mobility scooter to Runnymede Gardens, where he flagged down a member of the public for help.
