A man has been arrested on suspicion of murder after a shopkeeper was stabbed to death over a "few pounds worth of coins".
Ravi Katharkamar was knifed in the chest as he opened Marsh Food and Wine in Pinner, north-west London, on Sunday morning.
Scotland Yard said a 44-year-old man was detained in the London borough of Harrow on Wednesday in relation to Ravi's death.
A passer-by found him collapsed inside the shop suffering from stab injuries and police were called at about 6am.
London Ambulance Service also attended but Mr Katharkamar was pronounced dead at the scene 45 minutes later.
His attacker fled with a shop till - containing just a few pounds of coins - which police are still trying to find.
Describing the incident as a “vicious and unwarranted attack on a completely innocent man”, Detective Chief Inspector Simon Stancombe said: “Ravi’s attacker got away with a few pounds worth of coins, but he leaves behind a family utterly devastated and a close-knit community asking who could do such a thing.
“The attacker fled with a shop till – have you found this discarded or seen someone in possession of a shop till who wouldn’t normally have one? Do you know someone trying to use lots of loose change since Sunday morning?
“I am also keen to hear from anyone who has information about a black Vauxhall Astra that the attacker used to drive away from the scene.
“This was parked in Cecil Park prior to the murder and was driven off at speed, south down Cecil Park immediately after the attack.
“If you saw this car, or have seen a black Vauxhall Astra abandoned, please contact my team.”Officers remain in the area and are available should residents have concerns or information they wish to pass on.
Fundraising appeals have been launched to try to help Mr Katharkamar’s grieving family.
Anyone with information is asked to contact the incident room number on 0208 358 0200, via 101, or call Crimestoppers anonymously on 0800 555 111.