Undated handout photo issued by Lancashire Police of Tiernan Darnton
A student has been convicted of murdering his 94-year-old grandmother by setting her curtain on fire with a lighter.
Tiernan Darnton, 21, killed Mary Gregory – his stepfather’s mother – by starting a blaze at her bungalow in Heysham, Lancashire in May 2018.
When he was caught Darnton claimed it was a mercy killing but detectives found chilling internet searches on his phone including, ‘good alibi’ and ‘I want to cause evil’.
The pensioner was discovered under a table in the conservatory and died four days after the blaze in hospital.
An inquest in 2018 ruled that Mrs Gregory was the victim of an accidental fire after Lancashire Fire and Rescue Service concluded the most probable cause was a dropped or carelessly discarded cigarette and ruled out any third party involvement.
But police reopened the case in 2019 after Darnton told a counsellor he used a lighter to set a curtain on fire at the address.
He claimed he started the blaze because he did not want Mrs Gregory ‘to suffer any longer from dementia’, Preston Crown Court heard.
However, police examination of Darnton’s phone and laptop found internet searches made after the fire including ‘I’m a murderer’, ‘I’m a monster and I’m going to hell’, and ‘Urge to kill again’.
A month before the blaze – when Darnton was 17 – he also searched ‘Under 18 murder’.
Evidence shown to the jury included drawings found at Darnton’s home address, outlining the floor plan of the 94-year-old’s bungalow. They contained labels including ‘good hiding place’ and ‘quick exit’, as well as references to needing a ‘good alibi’.
A packet of Tunnock’s teacakes and a can of Coca-Cola, bought by Darnton from a nearby service station less than two hours before the fire, were also discovered at the scene.
During the inquiry it emerged the student had made a similar confession several weeks after Mrs Gregory’s death during a game of Truth or Dare with friends, in which he revealed his ‘darkest secret’.
He told them: ‘I have a secret I haven’t told anyone. I may have killed someone.’
The defendant closed his eyes briefly after the jury foreman returned the unanimous verdict and his stepfather rushed out of the courtroom as other members of the family broke down in tears.
Mary Gregory, who died following a fire at her bungalow in Heysham, Lancashire in May 2018
Evidence shown to the jury also included drawings found at Darnton’s home address outlining the floorplan of Mrs Gregory’s bungalow
Darnton, a former student at Kendal College and Lancaster & Morecambe College, was arrested at his family home in Combermere Road, Heysham, in May 2019
Evidence that placed Darnton at Mrs Gregory’s house around the time of the fire. This featured a packet of Turnock’s teacakes and a can of Coca Cola
Darnton’s friends did not believe him and he persuaded them to keep quiet, but he told a counsellor in May 2019 about a friend ‘who could send me to prison cos of what he knows’.
He added that he had felt ‘powerful’ at an event involving a person who had died – thought to be Mrs Gregory’s funeral – as he ‘knew what had happened and everyone else in the room didn’t’.
The female counsellor ended the session by saying to him ‘I’m not really clear what you’re saying but I think you’re trying to tell me you’ve killed someone’, to which Darnton mouthed ‘Yes’.
A week later he told the counsellor and his stepfather, Chris Gregory, 66, that he had started the fire and the matter was later passed to the police by the counsellor, the court was told.
Darnton, a former student at Kendal College and Lancaster & Morecambe College, was arrested at his family home in Combermere Road, Heysham, in May 2019.
Darnton killed Mrs Gregory by starting a blaze at her bungalow in Heysham, Lancashire
Giving evidence at his trial, Darnton said the case was ‘all a big misunderstanding’ and his confessions were false.
He said he only wanted to impress his ‘edgy’ friends in the Truth or Dare game and felt he had to say something believable, although he knew it was ‘messed up’.
Darnton said his comments to the counsellor that he had killed somebody were ‘attention-seeking’ but denied saying he had set his step-grandmother’s house alight.
He claimed his Google searches were related to his interest in killers and true crime, and said he did not even understand at the time the true definition in law of murder.
An investigator from Lancashire Fire and Rescue Service ruled in August 2018 that the probable cause of the fire at Mrs Gregory’s home was a cigarette and told the jury his opinion was unchanged.
When pressed, Darnton said he started the blaze because he did not want Mrs Gregory, formerly from Nuneaton, Warwickshire, to suffer any longer from dementia, Preston Crown Court (pictured) heard
However, a fire examination expert for the prosecution said the chances of that were ‘extremely remote’ and he believed the blaze was most likely started by naked flame ignition near the front bedroom window of the property.
The Crown said attempts were also made to hamper any escape by Mrs Gregory, with a table placed in front of the conservatory doors, the unplugging of a phone cable and the dismantling of a smoke alarm.
Mr Gregory, giving evidence for the defence, said Darnton – whom he home-schooled – had been suffering from depression for a number of years and was ‘plagued by intrusive thoughts which were very, very disturbing’.
He told the jury he would have taken Darnton to the police himself if he believed he had hurt his mother in any way.
Following the verdict, Detective Chief Inspector Zoe Russo, from Lancashire Police, said: ‘Darnton regularly visited Mrs Gregory’s home after her son took him under his wing at a young age. Darnton would spend time at Mrs Gregory’s bungalow and not only took advantage of Mrs Gregory’s kind nature, he also used his access to her home to meticulously plan his murderous act.’
Sentencing will take place on Friday.