Haroon, Abdul Musavir, 31, and Shazad Ali, 31, were mowed down as they stood on the pavement protecting their mosque and businesses in the community.
Today, a 32-year-old man was being questioned on suspicion of murder.
The father said he was standing round the corner as the car mounted the pavement and knocked down the three young men.
He said he acted instinctively and helped - without realising his boy was one of the trio who were fatally injured.
Mr Jahan said: 'The car came up on the pavement for God knows what reason and I was standing nearby.
'I heard it happen and I turned round and I saw three people on the ground and my instinct to help and I started CPR and someone told me that one of them was my son.
'I started CPR on my own son and my hands and face were covered in blood. What was the point in doing it? We are here defending the community. He was a good kid aged 21, and very well liked.'
Mohammed Chowdhri, who knew Haroon, said the three young men were on the streets protecting the mosque and businesses from rioters.
Source and full story: Daily Mail, 10 August 2011