The 1991 police investigation into the murders of Trevor Buchanan and Lesley Howell was deeply flawed, lacked objectivity and let down the families of both victims.
That is the main finding from an investigation by the Police Ombudsman's Office into police handling of the deaths of Mr Buchanan and Mrs Howell, who were found dead in a car parked in a garage at Castlerock in May 1991 in what was initially regarded as a 'double suicide.'
Lesley Howell's husband, Colin Howell, later pleaded guilty to both murders, which he staged to look like suicides, and has been sentenced to life imprisonment. Trevor Buchanan's wife, Hazel Buchanan, was subsequently convicted of both murders and sentenced to life imprisonment. She has since lodged an appeal against her conviction.
Investigation should have been more thorough.
Police Ombudsman, Al Hutchinson, has said the 1991 police investigation missed evidential opportunities and said the police should have conducted a more thorough investigation:
"There was a very early assumption of suicide. I have seen little evidence that this assumption was subject to any test or challenge by the investigators.
"For nearly two decades family members and close friends were left to cope with the thought that Trevor and Lesley had chosen to take their own lives. The families may never have had to live through this pain had the police conducted a thorough, searching investigation when they had the opportunity in 1991.
Evidential opportunities overlooked, lines of enquiry not fully explored and inconsistencies not considered.
"Evidential opportunities were overlooked or ignored, lines of enquiry were not fully explored and police did not consider the inconsistencies and discrepancies in the evidence which began to emerge. They accepted the accounts provided by Howell and Buchanan despite the fact that from quite early on in the investigation both were shown to be lying.
"These failures are all the more difficult to accept or understand given the fact that the investigation was conducted by two experienced senior detectives. I can only conclude that police failed the victims' families," he said.
The Police Ombudsman found that from the beginning of the investigation, when both bodies were found in the garage, police were faced with a scenario which was unusual in itself and this was exacerbated by a number of issues: the vacuum cleaner pipe which was used in the supposed suicide was only loosely fitted into the car's exhaust and had a kink in it; the supposed 'couple' were not sitting together; the driver's window of the car was fully down; the door was open and Trevor Buchanan's leg was sticking out of the vehicle.
Failures in handling of incident scene.
Police Ombudsman investigators found that police did not deal with the scene properly. The car was not forensically examined, many items in the garage, including the vacuum cleaner pipe, were not submitted for fingerprint examination and too few photographs and measurements were taken.
"The police did not maximise all the potential forensic opportunities in the garage nor fully investigate the inconsistencies which faced them. This would indicate that from an early stage they accepted the suicide theory and showed an investigative bias which was to pervade the investigation which followed," said Mr Hutchinson.
The Police Ombudsman investigation found that Post Mortem photographs showed injuries to Trevor Buchanan's mouth and nose area and what appeared to be blood coming from the back of his head. It found that police accepted Howell's account of how these injuries may have happened, and made no further inquiries about them despite at least two people raising concerns about the injuries at Trevor's wake.
Police failed to challenge Colin Howell about why he was so adamant bodies were in garage.
It found that although Howell made three attempts to direct people to the garage and to 'find' the bodies, police failed to challenge him as to why he was so adamant they could be found there.
It found that although police established quite early on in the investigation that both Howell and Buchanan had lied to them about aspects of their affair, they continued to accept them both as credible witnesses:
"No other aspects of their accounts were challenged, including Howell's account of his wife's movements on the day before her death, which was contrary to information given by other witnesses. There was other information provided to the police at the time which suggested Howell had been giving his wife medication, and had on one occasion dropped an electric cable into her bath and that he was having financial difficulties. All of these issues were disregarded."
Investigative bias towards suicide theory, despite Howell and Buchanan lying.
"Police continued to show an investigative bias and adhere to the suicide theory, despite the fact that the two main people promoting it, Howell and Buchanan, had lied to them," said the Police Ombudsman.
Among the other failures, the Police Ombudsman found that police did not explore the concerns brought to them by a serving police officer. They did not conduct any inquiries following the discovery of blood on Trevor's sweatshirt nor examine the discrepancies in the wording and phrasing of the apparent suicide note.