Important Corrections to the Documentary Transcript

The victims’ names were Lesley Howell and Royal Ulster Constabulary officer Trevor Buchanan. Colin Howell’s lover was known as Hazel Buchanan at the time of the murders and later became Hazel Stewart after remarrying.

Lesley and Trevor were murdered during the night of May 18–19, 1991. Their bodies were discovered on May 19 inside Lesley’s car, which had been staged in the garage of her recently deceased father’s property at 6 Cliff Terrace in Castlerock, County Londonderry. Trevor was positioned in the driver’s seat, while Lesley was placed inside the car’s boot rather than simply seated in the passenger compartment.

Colin Howell did not report Lesley missing several days before the discovery. He returned home at approximately 4:30 a.m. after staging the scene and contacted police that morning. He also contacted a church elder and repeatedly attempted to guide searchers toward the garage where he had left the bodies.

The transcript says Howell confessed in late 2008. The official court judgment states that he confessed to his second wife and members of Coleraine Baptist Church on January 29, 2009, and was arrested that same day.

The murders were concealed for approximately 18 years. Howell pleaded guilty in 2010 and received a life sentence with a minimum term of 21 years. Hazel Stewart was convicted by a unanimous jury in 2011 and received a life sentence with a minimum term of 18 years. Her most recent attempt to challenge the length of her sentence was rejected by the Northern Ireland Court of Appeal in June 2025.

Several dramatic biographical claims in the transcript, including three abortions before Colin and Lesley married, the exact circumstances of every pregnancy and the suggestion that Howell deliberately interpreted a particular note as a future murder alibi, are not established in the published judgments reviewed for this account. They should not be presented as confirmed facts.

Two Families in the Same Church Community

Colin David Howell was a dentist who lived with his wife, Lesley, and their children in the Coleraine area of Northern Ireland.

The family belonged to Coleraine Baptist Church, where Colin was regarded as a committed Christian and an active member of the congregation. His professional standing and church involvement allowed him to cultivate the image of a respectable husband, father and community leader.

Lesley had trained as a nurse and was the mother of four young children. People who knew her later remembered her as a warm, caring woman who was deeply devoted to her family.

Trevor Buchanan served as an officer in the Royal Ulster Constabulary. He lived with his wife, Hazel, and their two children in the same general community.

The Buchanan family also attended the Baptist church. Hazel worked with children in Sunday school, and the two families encountered one another through church services, youth activities and their children’s swimming sessions. Court records state that Hazel met Howell through the church and that their contact increased when he attended the swimming club in place of Lesley.

The Howells and Buchanans appeared to share the same religious values and family-centred lifestyle. Behind that appearance, however, Colin and Hazel began a sexual relationship.

The Affair Between Colin Howell and Hazel Buchanan

Hazel later told police that Howell telephoned her one evening and visited her home while Trevor was working. Their relationship became intense and sexual.

Because the affair involved two married members of a close church community, exposure threatened both families and the public reputations Colin and Hazel had built.

Hazel eventually informed the church pastor about the relationship, and the affair temporarily ended. The church became involved, and efforts were made to restore the two marriages and prevent further contact between the lovers.

The separation did not last.

Howell contacted Hazel again, and the relationship resumed. Hazel later became pregnant and said she did not know whether Howell or Trevor was the biological father. With Howell’s assistance, she underwent a secret abortion.

Hazel told police that her feelings toward Howell changed after the abortion. She described him as controlling, dishonest and attracted to risk. She claimed that other people had warned her he was a compulsive liar, but she had initially been drawn to his charm.

Those later statements formed part of Hazel’s defence. She argued that Howell dominated and frightened her and that she feared he might kill her if she refused to cooperate.

The prosecution maintained that, whatever Howell’s character, Hazel willingly participated in a joint plan to remove both spouses so that she and Howell could continue their relationship.

Lesley’s Emotional Crisis

Lesley discovered the affair and experienced a period of severe emotional distress.

Hazel herself told police that she believed the discovery of the relationship contributed to Lesley taking an overdose. Lesley survived, but the incident later became useful to Howell when he attempted to portray her death as suicide.

The transcript presents a detailed account of Lesley driving herself to hospital, begging doctors not to record the incident and later writing a specific farewell note. Those exact details are not fully established in the published court judgments.

What is confirmed is that Howell later produced what was treated as a suicide note supposedly left by Lesley at their home. The existence of the note became one of the factors that encouraged investigators to accept the staged suicide narrative.

A later review by the Police Ombudsman found discrepancies in the language and phrasing of the supposed note that police had failed to investigate properly.

The Plan to Remove Both Spouses

Howell later told the court that he developed a plan to kill Lesley and Trevor and present their deaths as a joint suicide.

According to his account, he discussed the plan with Hazel. Both spouses would be rendered unconscious or heavily sedated. Howell would introduce carbon monoxide from a vehicle’s exhaust while they slept.

Afterward, the bodies would be placed together in a car. Investigators would be led to believe that Lesley and Trevor, humiliated by their spouses’ affair, had chosen to die together.

The apparent suicide pact would provide an explanation for both deaths while removing the two people preventing Colin and Hazel from living openly as a couple.

Hazel initially claimed she had not understood how Howell intended to kill them. During a prolonged series of police interviews in 2009, however, her account changed substantially.

She eventually acknowledged that she knew Howell was coming to her home to kill Trevor and that carbon monoxide would be used. When investigators directly asked whether she had allowed Howell to murder both spouses as part of a plan in which she had been involved from the beginning, she answered yes.

The Court of Appeal later concluded that there was strong evidence from which the jury could find that Hazel knowingly and willingly participated in the joint plan.

Preparing Trevor for the Attack

Howell understood that Trevor was a trained police officer who might resist if he woke during the attack.

He gave Hazel sleeping tablets and instructed her to crush or mash them before placing them in Trevor’s food. Hazel disputed parts of that account and claimed Trevor took medication because he could not sleep.

The jury was entitled to conclude that she encouraged Trevor to consume medication so that Howell could enter the house and overpower him more easily.

Hazel also moved her own vehicle out of the garage so Howell could reverse his car into it. She left clothes available so Trevor could be dressed after his death and permitted Howell to enter the house with the hose used to carry exhaust fumes into the bedroom.

Those acts became central to the case against her. Even though Howell physically caused the deaths, the prosecution argued that Hazel supplied assistance, access and encouragement before and during the murders.

The Night of May 18, 1991

The murders occurred during the night following the second birthday of Colin and Lesley’s youngest son.

Lesley had consumed alcohol and had taken medication within a therapeutic range. She fell asleep at home.

Howell attached a garden hose to the exhaust of his car and carried the other end into the house. He positioned it near Lesley while the engine produced carbon monoxide.

Howell had expected her to remain unconscious and die quietly.

Instead, she began to wake.

At his sentencing, the court heard that Lesley stirred and called out the name of her oldest son, Matthew. Rather than stopping, Howell physically subdued her and ensured that she continued breathing the fumes until she died.

The therapeutic level of medication and alcohol in her body later helped support the impression that she had deliberately prepared herself for death. In reality, the court found that she had been murdered while asleep and defenceless.

Moving Lesley’s Body

Once Howell was satisfied that Lesley was dead, he placed her body inside the boot of the car.

He covered her with a blanket and placed his bicycle over her. The bicycle would later provide him with a way to return home after abandoning the car in Castlerock.

Howell checked that the children were still asleep and then contacted Hazel.

He told her that he had finished with Lesley and was coming to her house.

Hazel had prepared the garage and knew what was about to happen to Trevor.

Howell drove through Coleraine with his wife’s body concealed in the boot.

The Murder of Trevor Buchanan

When Howell arrived, Hazel allowed him into the garage and the house.

Trevor was asleep in the bedroom and had been sedated.

Howell connected another length of garden hose to the exhaust of his vehicle and carried it into the room. He placed the open end beside Trevor so that the fumes would collect around him.

Trevor began to stir despite the medication.

Howell then held the pipe against or inside Trevor’s mouth and physically restrained him while the carbon monoxide took effect. Trevor was conscious enough to struggle before he became unresponsive.

Hazel remained elsewhere inside the house while her husband was killed.

The transcript claims she sat with her hands over her ears. That particular image comes primarily from later narrative reconstructions rather than the central published judgment. The established fact is that she knew Howell had come to kill Trevor, permitted the attack and did not intervene.

After Trevor died, Howell dressed him in the clothes Hazel had left out.

Trevor had been wearing only boxer shorts while he slept. Dressing him was part of the effort to make it appear that he had voluntarily left the house with Lesley.

Hazel Cleans the House

Howell carried Trevor’s body to the car and placed it in the boot beside Lesley.

Hazel’s assigned role was to remove evidence from the Buchanan home.

She cut the garden hose into sections and burned the pieces in the fireplace. She washed bedding, opened the bedroom window to remove the smell of fumes and later supplied false accounts to police.

Hazel initially told investigators that Howell arrived unexpectedly and that she had not known what he intended to do.

Under continued questioning, she accepted that she knew in advance that he was coming to murder Trevor. She also admitted that Howell instructed her on what to say about her husband’s disappearance.

The destruction of the hose and the cleaning of the bedroom were not spontaneous actions performed by an uninvolved witness. They were steps that helped conceal a planned killing.

Transporting the Bodies to Castlerock

Howell drove away with both bodies in the car.

His destination was a vacant property at 6 Cliff Terrace in Castlerock. The house had belonged to Lesley’s father, Harry Clarke, who had died only a few weeks earlier.

Before reaching the property, Howell left his bicycle at a location from which he could later ride home.

He reversed the car into the garage and began arranging the scene.

Howell removed Trevor from the boot and placed him in the driver’s seat. He could not position the body naturally. Trevor was slumped inside the car with the driver’s door open and one leg extending outside.

Lesley remained in the boot.

Howell placed Walkman headphones on her and switched on the music player. Family photographs were arranged beside her body to suggest that she had been thinking about her children during her final moments.

An old vacuum cleaner was inside the car. Howell connected its hose to the exhaust pipe and positioned the other end in the boot beside Lesley’s head.

He started the engine to fill the car and garage with exhaust fumes, left the property and returned to his bicycle.

Howell then cycled home, arriving at approximately 4:30 a.m.

Manufacturing the Missing-Person Story

After returning home, Howell contacted police and reported Lesley missing.

He told investigators that she had left after an argument. He created the impression that she was emotionally unstable and might have gone away with Trevor.

Hazel supplied a corresponding account regarding her husband.

The two statements were intended to explain why Lesley and Trevor had disappeared at the same time and to establish the emotional basis for an apparent suicide pact.

Howell also contacted Jim Flanagan, an elder at Coleraine Baptist Church, and encouraged members of the congregation to help search for the missing pair.

He repeatedly attempted to direct searchers toward the Castlerock garage.

The Police Ombudsman later found that Howell made three efforts to steer people to that location. Investigators failed to challenge him about why he was so certain the bodies might be found there.

By ensuring that other people discovered the scene, Howell avoided appearing to have direct knowledge of the bodies’ location.

The Discovery in the Garage

Searchers eventually opened the garage at the Castlerock property.

The car was inside, surrounded by a strong smell of exhaust fumes.

Trevor’s body was slumped in the driver’s seat. The door was open, the driver’s window was fully lowered and one leg extended awkwardly outside the vehicle.

Lesley was lying in the boot with headphones on and photographs positioned beside her.

The vacuum hose was only loosely connected to the exhaust and had a kink in it. The ignition remained switched on, although the engine was no longer running when authorities examined the vehicle.

The arrangement was highly unusual.

The two supposed suicide partners were not sitting together. One was in the driver’s seat while the other was hidden in the boot.

The open door and fully lowered window would have allowed fumes to escape.

Trevor’s awkward body position was inconsistent with a peaceful joint death.

Nevertheless, police accepted the central appearance created by Howell: two betrayed spouses had apparently died together after discovering their partners’ affair.

The Post-Mortem Examinations

Post-mortem examinations determined that both Lesley and Trevor died from carbon monoxide poisoning caused by vehicle exhaust.

Small amounts of medication were present in their bodies, but the levels were therapeutic rather than fatal. A drug overdose was ruled out. Lesley had also consumed alcohol.

Trevor had injuries around his mouth and nose, as well as what appeared to be blood at the back of his head.

Those findings were consistent with Howell’s later confession that Trevor woke and was physically restrained while the hose was held to his mouth.

At the time, however, police accepted Howell’s explanation for the injuries and conducted no adequate follow-up investigation. At least two people raised concerns about Trevor’s condition during his wake, but their observations did not lead to a proper homicide inquiry.

The 1991 Investigation

The original Royal Ulster Constabulary investigation quickly became focused on suicide.

Detectives accepted the affair as the emotional motive. Lesley’s earlier overdose and supposed note gave the theory additional credibility.

Once investigators settled on that explanation, contradictory evidence received little attention.

The car was not subjected to an adequate forensic examination. The vacuum-cleaner hose and numerous objects in the garage were not properly tested for fingerprints. Investigators took too few photographs and measurements of the scene.

Police failed to investigate the impractical arrangement of the exhaust hose, the open car door, the lowered window or Trevor’s leg extending outside the vehicle.

They did not properly examine blood found on Trevor’s sweatshirt.

They also failed to investigate inconsistencies in the supposed suicide note.

The Police Ombudsman later found that investigators had established at an early stage that Colin and Hazel were lying about aspects of their affair.

Despite knowing that the two principal witnesses had supplied false information, detectives continued treating them as credible and accepted the remainder of their accounts.

Ignored Warnings About Colin Howell

Police received other information that should have caused them to examine Howell more closely.

Witnesses alleged that Howell had been giving Lesley medication.

There was also a report that he had once dropped an electric cable into her bath, an incident that could have indicated previous threatening or dangerous behaviour.

Investigators learned that Howell was experiencing financial difficulties.

None of those matters was investigated adequately as a possible motive or indication that Lesley was in danger.

A serving police officer raised concerns and argued that the deaths required a criminal investigation. Those concerns were not fully pursued.

The Ombudsman later concluded that the investigators’ early commitment to the suicide theory created a bias that affected the entire inquiry.

The Original Inquests

Inquests into Lesley’s and Trevor’s deaths were held on May 14, 1992.

The findings recorded that both had died from carbon monoxide poisoning. The deaths continued to be understood publicly as a joint suicide.

The staged scene became the official history of the two families.

Lesley’s children grew up believing their mother had deliberately abandoned them.

Trevor’s children and relatives were left to believe that he had entered a suicide pact with the wife of the man involved with Hazel.

For almost two decades, Colin and Hazel knew that this explanation was false.

Colin and Hazel Continue Their Relationship

After the deaths, Colin and Hazel did not immediately become an openly married couple.

They continued seeing one another secretly and gradually became more comfortable appearing together.

Court records state that they took their children on outings to remote beaches, stayed in hotels and regularly spent Friday evenings together at Hazel’s home.

The relationship continued for approximately five years.

It ended during the summer of 1996 after Hazel met another man.

Hazel later remarried and became known as Hazel Stewart.

Colin also remarried. His second wife was Kyle Jorgensen Howell, an American woman with whom he built a new family and a prosperous life.

The secret of the murders remained hidden.

Colin’s Professional Life and Other Crimes

Howell continued working as a dentist and became increasingly successful.

Behind his professional image, he committed additional offences against female patients.

Between 1998 and 2008, he indecently assaulted five women while they were under sedation at his dental practice. Some patients had requested heavy sedation because they were afraid of dental treatment and were unable to understand or resist what he was doing.

Howell later pleaded guilty to 12 counts of indecent assault.

In May 2011, he received a sentence of five years and six months for those offences, to be served alongside his life sentence for the murders.

The sexual offences demonstrated that the respectable public identity he maintained after 1991 continued to conceal serious criminal conduct.

Matthew Howell’s Death

In 2007, Colin and Lesley’s oldest son, Matthew, died at the age of 22 after falling down a stairwell at an apartment building in St Petersburg, Russia.

Matthew had been studying at the University of St Andrews and was in Russia when the fatal accident occurred.

The loss affected the entire family.

Later accounts indicate that Colin interpreted Matthew’s death as punishment for the murders. Some family members said he believed he had brought death into the family and that God had responded by taking his son.

That belief was part of the psychological and religious crisis that eventually preceded his confession, although it was not the only pressure affecting him.

The Lost-Gold Investment Scam

Howell also suffered an enormous financial loss.

He invested approximately £350,000 in a scheme supposedly connected to recovering Japanese wartime gold hidden in the Philippines.

The project was a scam. Howell received only a small number of nearly worthless coins and lost money that reportedly included savings intended for his children’s education.

The collapse of his finances, Matthew’s death, renewed personal problems and the weight of the secret contributed to a period in which Howell began speaking about confession and divine punishment.

It would be misleading, however, to portray his confession as a purely spontaneous act of remorse. Witnesses later described elements of pride and bravado in the way he recounted the murders.

The Confession of January 29, 2009

On January 29, 2009, Howell confessed to Kyle.

Kyle contacted senior members of their church and asked them to come to the family home.

In front of the church elders, Howell described how he had murdered Lesley and Trevor and staged the scene to resemble a suicide pact.

One elder later testified that Howell appeared to take pride in the cleverness of his deception and in having misled police for nearly 18 years.

The church leaders insisted that the confession be reported to authorities.

Howell was arrested that day.

He provided investigators with detailed accounts of the murders, including information that explained the physical anomalies in the garage and the injuries found on Trevor’s body.

He also implicated Hazel as a participant in the plan.

Hazel Stewart’s Arrest and Changing Accounts

Police arrested Hazel after Howell’s confession.

She initially denied being involved in the murders and attempted to separate her actions from Howell’s.

Her story changed repeatedly during 15 police interviews.

At first, she claimed Howell arrived unexpectedly with Lesley already dead in the boot and that she had not known he intended to kill Trevor.

She later admitted knowing Howell was coming to murder her husband and that carbon monoxide would be used.

She acknowledged moving her vehicle from the garage, allowing Howell into the house, leaving out Trevor’s clothes, disposing of the hose, cleaning the bedroom and repeating a false story prepared by Howell.

Hazel continued to claim that she acted because she was terrified of Howell.

She described herself as vulnerable, easily manipulated and afraid that he might kill her or harm her children.

Howell Pleads Guilty

Colin Howell initially denied the charges after his arrest but changed his pleas in November 2010.

He pleaded guilty to murdering Lesley Howell and Trevor Buchanan.

Because murder carries a mandatory life sentence in Northern Ireland, the remaining question was the minimum period he would serve before becoming eligible for consideration by the Parole Commissioners.

On December 3, 2010, Mr Justice Hart imposed a minimum term of 21 years.

The judge described the killings as cold-blooded, carefully planned and ruthlessly executed.

He emphasized that both victims had been asleep and defenceless. Even when they began waking, Howell did not withdraw. He physically subdued them and continued the attacks until they died.

Howell could first become eligible for parole consideration after serving the minimum term, but eligibility does not guarantee release.

Hazel Stewart’s Trial

Hazel pleaded not guilty and stood trial at Coleraine Crown Court in early 2011.

Howell became the prosecution’s central witness.

He described the affair, planning, medication, murders, cleanup and staged scene. He testified that the idea had been his but that Hazel knowingly cooperated.

The defence attacked Howell’s credibility and portrayed him as manipulative, sexually predatory and controlling.

Hazel argued that she was another of his victims and had acted under fear rather than as a willing partner.

The prosecution did not have to prove that Hazel personally held the hose to either victim’s face.

It argued that the two killings formed a joint enterprise. Hazel knew both spouses would be killed, assisted in preparing Trevor, provided Howell access, destroyed evidence and promoted the false suicide account.

The Jury’s Verdict

On March 2, 2011, the jury unanimously found Hazel guilty of murdering both Trevor Buchanan and Lesley Howell.

The verdict meant the jury rejected her claim that she had been only a terrified observer who became involved after the deaths.

On March 16, the court imposed a life sentence with a minimum term of 18 years.

The judge gave her a shorter minimum term than Howell because he had physically carried out the killings and exercised a degree of control over her.

Nevertheless, the court found that Hazel had knowingly helped create the circumstances in which both murders could occur.

Why Hazel Was Responsible for Lesley’s Murder

Hazel later argued that even if she had helped Howell murder Trevor, she had not participated directly in killing Lesley.

The Court of Appeal rejected that distinction.

The evidence showed that the entire purpose of the plan was to remove both spouses and portray their deaths as a joint suicide.

Hazel knew Howell was arriving with Lesley’s body in the car. She permitted the second murder and helped construct the cover story that depended on both victims being found together.

Her assistance with Trevor’s murder was therefore part of the larger plan that included Lesley’s death.

The Court of Appeal concluded that the evidence was entirely capable of proving that Hazel and Howell were “in it together” and that her conviction for Lesley’s murder was safe.

The Police Ombudsman’s Investigation

After the truth became public, the Police Ombudsman for Northern Ireland examined the original 1991 investigation.

The Ombudsman concluded that the inquiry had been deeply flawed, lacked objectivity and failed both victims’ families.

Investigators had made an early assumption of suicide and failed to test it properly.

They overlooked evidence, failed to explore important lines of inquiry and ignored inconsistencies in the accounts given by Howell and Hazel.

The scene was not preserved or processed to an acceptable forensic standard.

The car was not examined properly, potential fingerprints were lost, Trevor’s injuries were not investigated adequately and Howell’s repeated attempts to direct searchers toward the garage were never challenged.

The Ombudsman concluded that, had the original investigation been thorough and objective, the families might have been spared nearly two decades of believing Lesley and Trevor had voluntarily abandoned them.

The Second Inquest

After Howell’s guilty pleas and Hazel’s conviction, the original inquest findings could no longer remain as the formal record.

A second inquest was ordered to establish that Lesley and Trevor had been murdered in their respective homes rather than dying voluntarily in the Castlerock garage.

The new proceedings corrected the official record.

Both families emphasized that the change mattered because Lesley and Trevor had spent almost 20 years publicly identified as people who had participated in a suicide pact.

The new findings restored the truth: they had been drugged, attacked and killed by their spouses’ partners.

Hazel’s Appeals

Hazel repeatedly attempted to challenge her convictions and sentence.

In 2013, the Northern Ireland Court of Appeal rejected her effort to overturn the conviction for Lesley’s murder. She abandoned her challenge concerning Trevor’s murder. The court stated that there was no reason to doubt the safety of the conviction.

Further appellate proceedings also failed.

In 2025, Hazel sought permission to challenge the length of her minimum term using new psychiatric evidence. Her lawyers argued that she had been suffering from depression, trauma and coercive control when the murders occurred.

The Court of Appeal refused the application on June 25, 2025.

The judges concluded that the 18-year minimum term was neither wrong nor manifestly excessive. They noted that the original sentencing judge had already considered Howell’s control when imposing a shorter minimum period on Hazel than on him.

The court also emphasized the need for finality and acknowledged the distress repeated appeals caused the victims’ families.

Current Legal Status

Colin Howell remains subject to a life sentence for the murders of Lesley Howell and Trevor Buchanan, with a minimum term of 21 years.

He also received a five-and-a-half-year sentence for indecently assaulting five sedated dental patients.

Hazel Stewart remains subject to a life sentence with a minimum term of 18 years for both murders.

Her conviction remains legally valid, and her latest appeal attempt was rejected in 2025.

A minimum term is not a fixed release date. After completing it, a life prisoner may only be released if the relevant parole authority concludes that continued detention is no longer necessary for public protection.

Lesley and Trevor as Victims

The case was publicly framed for years around a supposedly scandalous suicide pact.

That false account overshadowed the people Lesley and Trevor had actually been.

Lesley was a 31-year-old mother of four who was asleep inside her home when her husband used exhaust fumes to kill her.

Trevor was a 32-year-old police officer and father of two who was sedated in his own home before being physically restrained and killed.

Neither chose to die.

Neither consented to be placed in the car.

The photographs, headphones, hose and apparent farewell message were props arranged to make the victims appear responsible for their own deaths.

Conclusion

During the spring of 1991, dentist Colin Howell and Sunday school teacher Hazel Buchanan were involved in a secret affair that threatened their marriages, families and standing within a strict Baptist community.

Rather than ending the relationship or accepting the consequences, they developed a plan to remove their spouses.

On the night of May 18, Howell used carbon monoxide to kill Lesley while she slept at home.

When she began to wake and called for her son, he physically restrained her until she died.

Howell concealed Lesley’s body in the boot of his car and drove to Hazel’s house.

Hazel had made the garage accessible, encouraged Trevor to take medication and left clothes ready for his body.

Howell carried a hose into Trevor’s bedroom. When Trevor awakened, Howell held the pipe to his mouth and restrained him until the fumes killed him.

Hazel cut up and burned the hose, washed the bedding and helped remove evidence from the house.

Howell transported both bodies to Lesley’s late father’s garage in Castlerock.

He placed Trevor in the driver’s seat, left Lesley in the boot, put headphones on her, arranged family photographs and connected an old vacuum hose to the car’s exhaust.

He then started the engine, left the garage and cycled home.

That morning, Howell and Hazel supplied matching stories suggesting that Lesley and Trevor had left together after discovering the affair.

Howell repeatedly guided church members and searchers toward the garage until the bodies were found.

Police accepted the appearance of a joint suicide despite the open car door, lowered window, loosely attached hose, Trevor’s injuries, suspicious body positions and inconsistencies in the witnesses’ accounts.

The official investigation failed to examine the car properly, ignored potential forensic evidence and continued trusting Howell and Hazel even after determining that both had lied.

For 18 years, Lesley’s and Trevor’s children lived with the belief that their parents had chosen to die together.

Howell continued practising dentistry, remarried, raised another family and sexually assaulted vulnerable female patients under sedation.

After the accidental death of his son, the collapse of a fraudulent investment and a personal religious crisis, Howell confessed on January 29, 2009.

His confession exposed the staged scene and Hazel’s participation.

Howell pleaded guilty and was sentenced to life with a minimum term of 21 years.

Hazel denied responsibility but changed her account repeatedly during police interviews. A jury unanimously convicted her of both murders, and she received life imprisonment with a minimum term of 18 years.

A later Police Ombudsman investigation confirmed that the original inquiry had been deeply flawed and had failed the victims’ families.

The second inquest finally corrected the public record.

Lesley Howell and Trevor Buchanan did not enter a suicide pact.

They were murdered in their own homes by two people who believed their religious reputations, carefully arranged evidence and coordinated lies would protect them forever.

For almost two decades, that belief appeared to be correct.

The case was solved only because Colin Howell eventually revealed the truth that the crime scene, the first investigation and the official records had failed to uncover.