A jury has heard the 999 call made on the day a Derbyshire taxi driver was found shot dead at a train station.
Stuart Ludlam, a 44-year-old father-of-three, was found in his taxi at Cromford railway station, in Derbyshire, on 17 September.
The emergency call made by a holidaymaker was played to the trial jury at Nottingham Crown Court.
Sixty-one-year-old Colin Cheetham from Ripley, Derbyshire, denies murdering Mr Ludlam.
The prosecution claims Mr Cheetham planned to lure a stranger to a secluded location to be killed.
Stuart Ludlam was discovered in the back of his cab at Cromford station last September.
He had been shot in the head.
Giving evidence, Peter Noble told the court he and his wife were on holiday in Derbyshire and had been visiting local sites including Cromford station.
He said as they were leaving, a passer-by flagged them down and asked them to call an ambulance and pointed to a car.
Mr Noble told the court he had started the to walk towards the car thinking there might have been an accident.
He said he could see glass missing from the back and an arm hanging out the car.
In the 999 call, Mr Noble said: "There's a mini-cab in the middle of the road and it looks like there's a body dumped into the back... there's a lot of blood.
"Oh my God...."
Prosecutor Peter Joyce QC asked: "Were you able to see where the blood was coming from?"
Mr Noble replied: "Not really. His head was wedged between the boot lid and the side of the car. He was in a ball... in a kneeling position.
"I could see blood but there was no obvious sign of injury," he added.
The trial continues.