A man has been arrested on suspicion of murdering a grandfather who was stabbed to death after he was involved in a minor crash on a village road.
Armed officers held the 34-year-old suspect, from Worthing, West Sussex, at 2pm in connection with the road rage murder of Donald Lock.
Mr Lock, 79, was knifed repeatedly in a "frenzied" attack after he got out of his car following the shunt on the A24 at Findon, near Worthing.
The suspect got out of the car in front and knifed the driver of the other car before getting back into his vehicle and driving off.
The victim, whose identity has not been revealed, died at the scene.
A Sussex Police spokesman said: "Police are investigating a fatal stabbing of a man following a collision between two cars on the A24, opposite the garden centre at Rogers Farm, Findon, just before 8.40pm on Thursday.
"A suspect who was in the car in front got out and stabbed the driver of the other car. The air ambulance landed and paramedics carried out first aid on the victim but he died at the scene.
"The suspect got back in the vehicle and drove off. Inquiries are ongoing to trace the suspect. The A24 is currently shut in both directions by the Black Horse pub."