Sussex Police have launched a murder inquiry after a 79-year-old male driver was stabbed to death by another motorist after the pair crashed into each other on the A24 near Findon, West Sussex.
Police said the suspect had been in the car in front when the incident happened at 8.40pm opposite a garden centre at Rogers Farm on Thursday (16 July).
The suspect drove off before an air ambulance team and paramedics arrived but the victim died at the scene.
The suspect is described as a white man, aged between 30 and 40, 6 foot tall, skinny with shoulder length brown wavy hair, with a thin face. His car is described as a pale coloured old style vehicle.
Detective Chief Inspector Karen Mizzi of the Surrey and Sussex Major Crime Team said: "Officers have been urgently making enquiries overnight to trace the suspect. We need to hear from witnesses who saw the collision, the suspect or the car involved, particularly if anyone filmed the incident or saw anyone filming it. Specially trained officers are supporting the victims family at this extremely difficult time."
A section of the A24 southbound at the junction of Cross Lane, Findon, remains closed. A diversion is in place.
Anyone with information can contact Sussex Police by ringing 101, or email email@example.com quoting Operation Roseberg, or call the independent charity Crimestoppers anonymously on 0800 555 111.