The gang who killed drug dealer Steven Crook were trapped by their own drug fuelled arrogance and detectives using the full range of modern forensic tools.
The three men from Coventry and one from Devon were high on drink and cocaine when they carried out the attack and they left a trail of clues before, during and afterwards as a result.
They were men living beyond the edge of society who were desperate for drugs or money to feed their habits and propelled by violent bravado.
The inquiry which brought them to justice used mobile phone data and number plate recognition technology to track the movements of the five men and shoeprint analysis to work out what had happened inside the victim's flat.
Fingerprints found on the property stolen in the bungled robbery provided key evidence to tie in other members of the gang but the most crucial clues came from CCTV.
Images taken inside the Sainsbury store just yards from the murder scene were central to the case against the four men because they showed them all together moments after four knives were bought.
All the men denied knowing that a violent robbery was being planned but the Sainsbury footage showed Darren Twigger peeling off from the rest of the group and buying the knives.
He did not have a basket or a trolley and he could be seen holding them out in front of him as he turned into an aisle and rejoined the rest of the gang, who could have seen what he had in his hand.
Different CCTV footage showed police what happened after the raid on 43-year-old Mr Crook's home in Alphington Road on the evening of November 21 last year.
Images from the Spice Lounge in Exmouth showed key player Ryan Singleton re-enacting the killing as he showed getaway driver Steven Webster what had happened inside Mr Crook's flat.
In a chilling section of the tape he can be seen rubbing Webster's hair. There is no sound but Webster later revealed he was boasting of slashing Crook and 'making a chess board of his head'.
More footage from the Exeter Arms Hotel, just opposite police headquarters in Middlemoor, showed the entire gang celebrating the robbery late into the night.
Singleton was even seen by a camera behind the bar flashing the £1,000 roll of stolen banknotes as he tried to bribe the barman into serving him after time.
The murder inquiry started when Mr Crook's girlfriend Karlina Beaumont came home from getting a Chinese takeaway to find him fatally injured and the flat turned into a bloodbath.
The first breakthrough came hours later when Singleton was found staggering around Cowick Street after using the stolen cash for a drink and drugs spree that had left him barely able to stand.
He had a room at the Exeter Arms Hotel but had wandered off into the night and taken a taxi into the centre of Exeter in the hope of buying more drink and cocaine.
Staff at an all night supermarket called police because they thought he was a drink driver but once arrested he was linked to the murder within minutes because his trainers were caked in blood.
Forensic analysis of the murder scene allowed detectives to build up a details picture of the killing.
They showed the initial attack happened as Mr Crook opened his back door to the intruders. He almost certainly suffered his fatal injuries in a struggle just inside the flat which left blood caked on the walls and floor.
Experts were able to trace the progress of the victim and Singleton, Twigger, and fellow intruder Anthony Martin through the flat.
The only set of trainers recovered by police were Singleton's and showed him going through the kitchen and living room to the bedroom, where Mr Crook kept his cash and valuables.
Mr Crook's own footprints showed a similar path and suggested he had been forced back into the flat and slashed across the head, possibly to make him tell the gang where he kept his cash and drugs.
Twigger and Martin were not arrested immediately and so had the chance to dispose of any shoes or clothing linking them to the attack, but the footprints showed the presence of Singleton and at least two others.
Once Singleton was in custody police set about identifying the rest of the gang. They were able to do this by several different techniques.
The key evidence came from his phone, which had contacts for Webster and Martin but there was also DNA and fingerprint evidence from some of the items stolen from Mr Crook's flat.
Some of these were found at Crabb Lane, Ide, by a dog walker and others were found either hidden or discarded in the two rooms the men had used at the Exeter Arms.
They found images from the CCTV in Devon and at a motorway services in Somerset where four of them had stopped on their way down from Coventry.
The phone evidence enabled them to pick up Webster and to piece together the origins of the chaotic plan which ended in the attack on Mr Crook.
Webster was a small-time criminal and long term heroin addict who had lived in Exmouth and Exeter and knew Mr Crook because he had bought drugs from him in the past.
He owed Mr Crook £3,000 for a car which he bought by promising installments which he never met.
Mr Crook dealt drugs on a substantial scale but like most dealers kept very little cash or stock at his home, using customers who owed him money as warehousemen or money launderers.
Webster knew where he lived and the exact arrangements for security at his flat, enabling the other four to get in.
He met Singleton when they were on the same landing at Channings Wood Prison near Newton Abbot a year before the killing. Webster was serving 30 months for fraud while Singleton was inside for a burglary in Bristol.
They became friends and stayed in touch after they were both released. Both entered a murky subculture of drug dealing; Webster in Devon and Singleton in his native Coventry.
Webster was a heavy user whose addiction was so strong that in the past he had used other people's urine to falsify drug tests when he was supposed to be receiving rehabilitation.
He started acting as a middle ranking pusher for a larger scale dealer who operated out of Tavistock. He bought more than he needed for himself and financed his habit by selling the surplus to fellow addicts in and around Okehampton.
Singleton was a runner for Martin, who was a dealer in the Canley area of Coventry, but he had ambitions of moving up the feeding chain.
The first contact came when Webster arranged a £800 heroin deal through his dealer in Tavistock and Singleton and Martin drove to Devon for a rendez-vous at a filling station on the A 30 at Launceston three days before the attack on Mr Crook.
The next day Singleton and Webster exchanged texts which showed they were planning a campaign of attacks on dealers.
One message spoke of getting £20,000 in cash or drugs and another from Webster to Singleton said 'three to rob next time, big money next time you are down, keep it between us'.
Another said 'let me show my face and get intel. In and out, go in hard, no f***ing about'.
In the end they carried out only one attack after Webster persuaded them to leave his own dealer alone.
Singleton came down with Martin, who he knew as Cabbage, and the other two. Twigger was recruited because he was the only one with access to a car on the day.
He was a well paid cable layer but had a cocaine habit which had led him to get into debt. Richardson, who was just 17 at the time, knew Singleton and Webster and joined the expedition to Devon.
The jury are still deliberating about his guilt or innocence and what, if anything, he knew of the plan to attack Mr Crook.
The progress of the gang on their trips to Devon was traced by police using cell site analysis, which showed exactly where each of their mobile phones were used, and number plate recognition, which tracked Twigger's car.
They picked up Webster in Okehampton and set off for Exeter where they went to Sainsbury to buy the knives and on to Mr Crook's home, parking in a back street near the alley that led to his rear door.
Webster stayed in the car while one of the others posed as a buyer to get past Mr Crook's tight security in which the only access was through his back gate, which was fortified and protected by a CCTV camera.
The intruders would normally have had to get past his dog, but Karlina had taken the Staffie with her to the take-away.
The men who went into his yard each gave differing accounts of what happened next which minimised their role in the violence while blaming the others.
The most likely scenario is that Mr Crook opened his back door to Singleton but then saw the other men behind him.
He slammed the door shut, trapping Singleton's arm in it but the others heaved it open and Martin passed one of the knives to Singleton.
Mr Crook suffered multiple stab wounds as they set on him inside the doorway, leaving a large pool of blood on the floor and spurts of blood splattered up the walls and the inside of the door.
They took him to the bedroom where they ransacked drawers until they found his cash box and some jewellery and they fled taking his laptop and Karlina's pink bag.
The level of violence owed much to the hyped up condition of Singleton, who had fortified himself with Dutch and Columbian courage by drinking Stella Artois and snorting cocaine in the car.
After leaving the flat they went to Exmouth, possibly in search of another target, possibly to buy more drugs, and then returned to celebrate at the Exeter Arms.
The evidence of the CCTV at the hotel and the Spice Lounge showed the men were completely unfazed by what they had done and were far more interested in spending the money than in the fate of their victim.
They only learned that Mr Crook had died when Twigger and Martin were on their way back North and a friend from Coventry sent a page from a local news website in Exeter to their smartphone.
Their response was to run and to destroy as much evidence as they could, but it was too late. The clues they had already left in Exeter meant the police were already on their trail.
They blamed each other for the violence but were convicted on the basis of joint enterprise, a legal principle dating back hundreds of years.
It meant the prosecution did not have to prove the exact role of each defendant, merely that they knew a robbery was going to take place and anticipated the possibility of some level of injury to the victim.
Steven Webster, aged 40, of East Street, Okehampton; Ryan Singleton, aged 26, of Howcotte Green, Canley, Coventry; Darren Twigger, aged 40, of John Rous Avenue, Canley; Bradley Richardson, aged 18, of Prior Deram Walk, Canley; and Anthony Martin, aged 22, of Gerard Avenue, Canley, all denied murder and robbery.
Singleton was found guilty of murder and robbery, Webster, Twigger and Martin of manslaughter and robbery.
The jury have yet to reach verdicts on Richardson. They will be sentenced next week.
