Siraperakash Supramaniam, 33, returned to his store - Haran Food and Wine on Harrow Road - to find a man arguing with
his wife. He was attacked after following the man out of the store.
Siraperakash was taken to Central Middlesex Hospital but was pronounced dead shortly after arrival.
Detectives said it appeared that robbery was not a motive for the attack. Two other men and a woman were arrested, but have since been released without charge.