Police have released CCTV images of a knifeman after an elderly busker was stabbed to death.
Thomas O'Halloran, 87, was attacked on a street in Greenford, west London yesterday afternoon.
He was pronounced dead at the scene and no arrests have been made.
Detectives have now shared pictures of a man who they want to identify "as a matter of urgency".
He was wearing grey shorts, a dark coloured t-shirt, a white baseball cap and white patterned builder style gloves.
Detective Chief Inspector Jim Eastwood, who is leading the investigation, said: “We are keen to identify the man in the CCTV images as a matter of urgency.
"He is clearly a dangerous individual and people are advised not to approach him, but to call us immediately on 999 if they know him or have any information regarding his whereabouts.
“My team and I have been working around the clock to bring Mr O’Halloran’s killer to justice, but we need your help.
"If you have any information at all that will assist us with our investigation – no matter how small – please contact us or alternatively, contact Crimestoppers anonymously.
“I’d also appeal to anyone who might have dash cam or cycle helmet footage that might have captured the incident to get in touch with us.”
Kind Thomas had been playing his accordion to raise money for Ukraine outside a Tesco superstore a mile from where he was stabbed, store staff told the Mirror.
He kept the money he raised in a yellow box on his scooter, a Tesco security guard said.
The same security guard claimed that he recognised the man pictured by police fleeing the scene as a local shoplifter who allegedly attempted to pinch from the store before.
“He wasn’t in the store yesterday but the old man was playing, he plays outside here every afternoon,” he said.
“I think the man will have followed or chased Thomas. He was raising quite a lot of money.”
Frasley Coutinho, who lives opposite the scene, earlier said he saw the victim surrounded by a group of young boys.
He said: "I saw a couple of people gathering around him and then he drove past and stopped further up, and then there was a group of young boys around him.”
Mr Coutinho said he caught some of the incident on a CCTV camera but it was obscured by a plant.
“I had a rose plant blocking it so I couldn’t see any more,” he said.
Speaking today, Western Area commander Chief Superintendent Sean Wilson said Thomas had his life “snatched away” in an act of “unprovoked violence”.
“He was a very well known and much-loved member of our community.
Thomas, who posted videos of himself playing the accordion and harmonica, was well-known in the area for busking outside the local Tube station and Tesco store.
Members of the community took to social media to share their fond memories of him, describing him as a "lovely" man who "helped everyone he could".
Hitesh Patel, a shop owner at Greenford Station, said he would play his accordion to raise funds for those affected by the Russian invasion of Ukraine.
He told the Evening Standard : "He always had a Ukraine flag on the front of his basket. It said Help for Ukraine as he played. He was very good, kind man.
“I saw him just before he was killed heading up to the A40 on his scooter I was filling up with petrol but I wish I had said something."
Speaking today, Western Area commander Chief Superintendent Sean Wilson said Thomas had his life “snatched away” in an act of “unprovoked violence”.
“He was a very well known and much-loved member of our community.
“Detectives have been working tirelessly over the last 20 hours to understand what has happened and to identify who was responsible for this horrific crime.”
He earlier said during a press briefing: “I understand that our community will quite rightly be shocked and appalled by this incident, as I am too.
“We are now able to name the man who has tragically lost his life as Mr Thomas O’Halloran who lived in Greenford and was a very well-known and much-loved member of our community.
“My thoughts very much remain with Mr O’Halloran’s family and friends today.
“I’d also like to appeal for their privacy to be respected while they come to terms with their loss.”
He added: “As of now, the public will see extra officers patrolling the area over the coming days. They are there to protect you and to help you.
“If you have any concerns or information that you want to share, please approach those officers.
“I realise the dreadful impact that incidents like this have on our communities – I would like to reassure you all that we are doing all we can to solve the horrendous crimes that we have seen across London over the last few days.
“I stress that London remains one of the very safest cities in the world.
“However, we do need your help and so please come forward with any information that you have about this awful incident or any other violent crimes."
Despite reviewing CCTV and carrying out forensic examinations, he called upon help from the public.
They believe he was stabbed in Western Avenue, Greenford, shortly after 4pm, before managing to travel around 75 yards on his mobility scooter to Runnymede Gardens where he flagged down a member of public for help.
Witnesses should call police on 101, referencing CAD 4691/16 Aug.
