THE DOUBLE-GLAZED WINDOW SALESMAN WHO WAS SOLD A DOUBLE MURDER - Kevin Cotterell

Look at Kevin Cotterell's mugshot after his arrest and you will see a troubled man. And, judging by the expression on his face as he looks into the camera, his demons are not within him but without.

Cotterell is doing a double life sentence for the murders of an elderly mother and her daughter after he had sold them a double-glazed window the previous year. Cotterell told the police that he had only called on them once to sell the window, and he protested his innocence while he was in police custody. Then he surprised everyone by entering a plea of guilty at the last moment before the trial.

This case may well be important because if he was innocent, then he has been fitted up with DNA forensic evidence and he preferred to plead guilty rather than challenge the evidence or face the trial. His behaviour would resemble that of Ian Huntley therefore. And if he was innocent, then this conviction should please Mrs Thatcher, because it would be a successful case of double-glazing salesmanship all round.

The victims were Janice Sheridan, aged 45, and her mother Constance Sheridan, aged 70. Cotterell was only 33. The daughter was a successful dog breeder and she and her mother lived with more than twenty whippets in their isolated cottage in the village of Upwell, on the border of Norfolk and Cambridgeshire, at the end of a winding narrow drive-way. The setting is somewhat eerie, the village just three feet above sea-level. Their bodies were found partly clothed, with multiple stab wounds, and Janice was bound with black masking tape. The police believed that the bodies had lain in the house for some days, and the knife was never found. Janice Sheridan was last seen by witnesses the previous Thursday walking her dogs. The bodies were discovered on Sunday, 10th January 1999.

The Sheridans had been burgled two years before, and the daughter Janice was involved in a dispute with travellers, who she wished to prevent moving into the village. At first it was thought that the motive might be connected to these, or to her success in the dog-breeding circuit.

The police described the murders as ruthless and determined, and the binding of daughter Janice suggests that either she was kept alive after her mother was murdered, or else that she was restrained while the killer waited for the mother to return home.

A reward was offered by the police, their justification being that it might save money in the cost of the investigation. This consideration might well explain why Kevin Cotterell is now in jail. No one apparently came forward to collect the reward, unless it was the witness who claimed that he had taken down the registration number of a "suspicious" car parked outside the cottage. When the police investigated this they got a partial identification of Cotterell's car number plate. Cotterell later claimed that he had visited the cottage the year before, in 1998, and that he had sold the Sheridans the window, and that he had not had contact with them since.

Another witness was reported to have seen "a similar green car" being driven away by a man wearing a "Bobby Ball" wig on Friday, the day after Janice was last seen walking her dogs. If this sighting were relevant, which it must be, it would mean that the killer had been wearing a disguise, and that he had stayed in the house with the whippets all night. He would therefore be likely to be known to the area, hence the disguise, and the police believed from the evidence of the crime scene that the killer must have been known to the victims.

This murder requires an explanation as to motive. The body of Janice Sheridan was found with her breasts exposed and her trousers removed and her panties pulled down, but this was not a sexual murder, as there was no sign of sexual assault or interference, and she was aged 45 and with her mother. The interference with her clothing suggests that the killer was a man and that he wished to humiliate her. This was apparently a sexist gesture rather than a sexual one, and it suggests that the killer must have been annoyed with her. It also indicates that the killer was known to the victims and that he had a personal grievance against Janice Sheridan. This does not agree with Cotterell's relationship of a successful sale the year before. Janice Sheridan was the successful dog breeder and the active opponent of the travellers in the village.

Because of their choice of culprit, the police have not been able to provide a motive for the murder, even after Cotterell's conviction, and everyone knows that in order to detect a murder, and in order to prove the case, it is necessary to find and prove the motive. The successful sale of a double-glazed window is hardly appropriate. There was no sexual assault or robbery to account for the crime, and Cotterell had no history of murder or violence. There is no precedent for this attack in his history.

The neighbours were horrified by Cotterell's plea of Guilty, because it meant that they were not going to learn why the victims had been murdered, and they wanted to know. Their bewilderment is understandable, because the earlier police supposition that the dispute with the travellers in the village, or something to do with the victims' success in the dog-breeding circuit, was the most obvious line of inquiry for a double murder that had no other identifiable motive.

The man that the police pulled in for questioning had had two juvenile convictions for burglary in 1983, when he was aged seventeen, but this factor didn't accord with the police belief that the killer was known to the women and that the attacker had been allowed inside the house, and nor did it accord with the burglary that the two women had previously experienced, because this happened a year or so before Cotterell visited them and sold them the window.

The case against Cotterell is founded entirely on the forensic evidence, which consisted of a fingerprint allegedly found inside the house, and a shoe print also, and his DNA in the knife wounds in Janice Sheridan's chest, and Janice and Constance Sheridan's blood on a Kleeneze bag taken from inside Cotterell's residence. He was then working for Kleeneze, so that the prosecution connects him to the Sheridans by two different jobs.

This forensic evidence creates a ludicrous scenario for a criminal psychology, in which a salesman, having changed his job, returns to a customer with whom he has had a successful transaction in the previous job and murders them. The psychology that this suggests is of an absurd homicidal professional closure. The profile for this killer looks like a designer psychopath with a police professional psychology behind it.

There are several odd-looking ironies in this prosecution, including the blood-filthy "Kleeneze" bag, the salesman who returns to murder a customer with whom he has had a happy professional transaction, the defendant's DNA being found in the chest wounds of one of the victims in a murder that was not sexually motivated, and there is the implication of the double-glazed window salesman fitted up with a double-glazed murder conviction.

Suspicions about Cotterell's prosecution and conviction arise from various angles. Firstly there is the lack of any motive, then there is the lack of any appropriate history. Then there are the photographs of Cotterell in police custody, in which he looks as homicidal, or as psychopathic, as Shakespeare or Defoe would in his position. He does not look guilty. There is a range of internal lights in the faces of psychopaths and criminals facing police cameras and these are all missing. He looks like a tired man, puzzled and resigned. He looks criminally negative. He looks like you could trust him to sell you a double-glazed window.

Another reason for suspicion arose in a recent ITV documentary on the case, in which the police described their investigation and prosecution of Cotterell. This programme featured a familiar criminal profiler who gave psychopathic explanations for behaviour that corresponds with innocence, including a lack of remorse. He and the police kept fitting Cotterell to the profile that they wanted, and this occurred throughout the programme and their investigation. If Fred West was not remorseful about his victims or his murders, he was certainly remorseful about where they had got him. Cotterell appeared throughout as a bewildered man, with the police seeing evidence of guilt in everything that he said or did. He looked a classic case of a man being determinedly misunderstood by prejudice. And this is also how he was presented as the murderer in this documentary.

Until the appearance of this forensic evidence, the police interest in Cotterell as a suspect had no justification or weight, and all the components of this conviction look odd. This case resembles the difference that exists between the needs imposed on the police by the courts for successful convictions and the requirements for proper detection.

The killer that this forensic evidence has convicted is unconvincing, and in view of what has happened to Huntley and Whiting since, it looks suspicous. We need to know the motive.

The reason that the friends and neighbours of the Sheridans were left mystified and frustrated by this investigation is surely because it has put the wrong man in jail, while the most likely explanation for the murders remains tantalizingly evident and unresolved.

Doubts over Cotterell's car

According to a report by the BBC, which was published prior to the identification of Cotterell's car, the police were apparently looking for a green car. A witness noted down a car registration number - G567 PVF - because he thought that the car looked suspicious. The BBC reported that "a similar green car" was driven away from the scene by a suspicious man in a "Bobby Ball" wig. Given the timing, the isolated situation of the house, and the disguise, this sighting must be relevant to the crime itself.

According to a local journalist in the Fenland Citizen recently, who had watched a TV documentary about the case on a video, the car that was identified as Cotterell's was a silver Rover, with the number G567 HVP.

Police suspicion fell on Cotterell after his car was noticed by a police officer who was driving along in the opposite direction at night, when colour recognition would not have concerned the officer, and he may only have had the time to recognize the first set of numbers where the partial match occurred.

If the car that the police had originally sought had been green, and Cotterell's silver, then the two factors that this police officer may not have noticed did not agree, namely the colour and the last set of numbers in the number plate.If the colour of Cotterell's car was different to that of the suspicious car, and the number differed on two counts also, then police interest in Cotterell's car would not be justified, and furthermore, the odds of his being responsible for the DNA evidence with which he was later convicted would surely exceed the most extravagant claims for identification by DNA matching.