DETECTIVES were convinced from the start that Andrew Hill was the prime suspect in the disappearance of Sheffield GP Colin Shawcross.
There was the powerful motive of jealousy but without a body it was always going to be difficult to build a case.
In the end, a combination of old-fashioned policing and the latest technology resulted in the successful prosecution at Sheffield Crown Court of Andrew Hill, the husband of Julie Hill, Dr Shawcross's lover.
Forensic evidence indicated it would not have been possible for somebody to have lost the amount of blood that was found at the GP's home without urgent medical attention. Police also had a neighbour's account of a man striking out with a length of wood, accompanied by groaning noises.
To confirm their belief that the GP was dead, detectives contacted every hospital and dental surgery in the country to confirm nobody of his name had been treated or registered as a new patient.
They also checked every supplier of gas, water, electricity and satellite and cable TV to see if Dr Shawcross had registered in another part of the country.
Every bank and mobile phone provider was contacted, along with ports and airports.
There was no trace of Dr Shawcross.
Meanwhile, another team was working on trying to find the body, searching ponds, woods and wasteland in South Yorkshire and neighbouring counties.
On the basis that Dr Shawcross's own car had been used to hide the body, they checked petrol records to see how much fuel would have been in the tank on the night of the attack and how far it could have been driven.
Attention began to centre on the Aston area after a police dog handler remembered seeing Dr Shawcross's distinctive burgundy Jaguar with its personalised number plates on a secluded track near fishing ponds close to the doctor's home on the night he was killed, January 23.
Andrew Hill was behind the wheel of the car and he told the officer the vehicle was his and he had run out of petrol.
When the police officer heard of the murder the following day, he told bosses what he had seen and underwater search teams were immediately sent in.
The search proved fruitless and moved to other stretches of water when it was discovered that Hill was a keen canoeist.
Using CCTV footage of Dr Shawcross's Jaguar and Hill's car to help piece together the killer's movements on the night of the murder, detectives were able to establish how long he had to dispose of the body – four hours – and worked out how far he could have travelled in that time.
Their search took them to Deepcar, Rother Valley Country Park, the River Don, the canal basin at Tinsley and Clumber Park in Worksop as well as Humberside, Matlock and a district near York.
Police also had Dr Shawcross's car forensically examined and enlisted the help of soil and pollen experts to suggest where it may have been.
After dogs detected a scent in Loscar Woods, Harthill, police found a wheelbarrow among the trees.
One officer was then given the job of sifting through every photograph and home video in Hill's house to see if there was an image of the same wheelbarrow.
A photo in the loft showed Hill building a patio in his garden – with a wheelbarrow. Experts then found markings that matched the one in the woods.
Five months after the killing, Dr Shawcross's remains were found buried behind a tree stump. A forensic scientist said the grave was the deepest she'd ever seen dug by hand and the choice of grave site had "required some planning".
She said it appeared to have been dug by someone who was used to digging holes – a job Hill did as a telecoms engineer.
The doctor had suffered skull fractures, there was a belt around his neck and he had a broken arm.
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. There were stones placed on the body as if to weigh it down.
Although they accepted the police theory that Dr Shawcross had been killed, his wife Carol and their grown-up sons James, Edward and Richard now knew for certain.
In a statement read during the trial, Carol Shawcross, aged 60, also a GP, said: “We had a long, happy, productive marriage. We had three children, who are all well-educated and in professional careers.
“He never truly left home. We would have sorted out our marriage difficulties.”
She paid tribute to her “well respected, caring” husband, describing a popular man devoted to his family and collection of cars.
He was first posted to Carterknowle Surgery in Sheffield, then moved to Firth Park Surgery in 1978, where he remained until retiring 30 years later.
Carol said: “He was a well-respected, caring doctor, viewed as the consummate professional by all who knew him.”
Later, Colin Shawcross carried out endoscopy work at the Royal Hallamshire Hospital, which is where he met Julie Hill.
Last March, he was due to receive an award at Sheffield Town Hall, recognising his years of service at Firth Park.
It was not to be but unless Hill talks after his conviction it will never be known whether he set out to kill Dr Shawcross.
Det Supt Mick Mason said: “We will never know if he snapped or what his intentions were – whether he deliberately went to kill Colin or whether he made that decision halfway up or right outside. Who knows?
“I think he went with the intention to kill. I think he had formed the intention when he left home.”
At times, the enormity of the case was overwhelming, said DS Mason, but police were determined not to give up.
“We all said we would find Colin. We were adamant we would find him, it was just the length of time it would take.”