Police have begun a murder investigation after a man was shot dead at a petrol station.John Pordage, 34, died after the attack at the BP garage near the Army and Navy roundabout in Baddow Road, Chelmsford, Essex, at around 2.10am on Saturday.The victim was with another man, aged his 20s, when a blue Ford Fiesta pulled up and Mr Pordage was shot by an occupant of the car, Essex Police said. He later died in hospital. Detectives praised members of the public who rushed to his aid and appealed for witnesses to come forward. One witness who was passing by the petrol station at the time told told Essex Live: “When I got there, there was two boys who said they were his friends.”He was already receiving CPR. I offered to carry on and take over but the man giving CPR said he was OK.”The ambulance were on their way, but because a firearm was involved, police had to be on the scene first. The police turned up and ambulance followed 10 seconds afterwards.”Senior investigating officer, Detective Chief Inspector Stephen Jennings, of the Kent and Essex Serious Crime Directorate, said: “We are progressing our enquiries and believe this incident involved people known to each other. The victim was allegedly friends with the man that shot him. Above, the scene on Saturday morningCredit:Stephen Huntley/HVC “We have spoken to a number of witnesses but I am keen to speak to anyone who saw what happened and has yet to come forward. Any information you have, however small you think it may be, could be vital in assisting our investigation.“I also want to speak to anyone who saw a car matching the description of the suspect vehicle in the area before and after the incident and anyone who took mobile phone or dash cam footage of the incident.” Drive-by shooting victim John PordageCredit:SWNS.com “Several members of the public went to the aid of the victim and his friend, and I want to thank them for their assistance in what clearly would have been harrowing circumstances. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.