Police have named the victim who died from stab wounds in Barrack Road, Northampton, as a father-of-two from the town.
Jon Casey, 35, from Ecton Brook, in Northampton died after the incident on Friday.
Paramedics were called to the scene near Lazeez restaurant at 5.25pm and transferred Mr Casey to Northampton General Hospital where he died of his injuries an hour later.
A passer-by and her young son tried to help Mr Casey with first aid before the emergency services arrived.
His family have been informed and a post mortem investigation was being carried out today by a Home Office pathologist in Leicester.
Det Insp Mark Brayfield, from Northamptonshire Police, said detectives were now following a number of lines of inquiry.
He said: “This was a brutal and ultimately fatal attack and we would urge anyone in the area at the time and who may have seen anything suspicious to come forward.
“We are very keen to know of Mr Casey’s movements in the hours leading up to his death,” he added.
Anyone with information should call Northamptonshire Police on 101 or, alternatively, Crimestoppers, on 0800 555111