Today moving statements were read out on behalf of her parents, Rebbecca Cooper and Bradley Smith, who said he was ‘pure evil’ and a ‘monster’.
In her statement Ms Cooper said: ‘I will never forgive you for this.’
Mrs Justice Juliet May jailed Mays for life with a minimum term of 25 years but ruled she could not be sure it was sexually or sadistic in its motivation.
However, she did rule Mays ‘intended to kill’ the teenager when striking her repeatedly in the clearing at Havant Thicket, not just cause really serious harm.
Sentencing, Mrs Justice May said Mays ‘terribly murdered’ Louise and the death of a vulnerable child was ‘particularly grievous’.
The judge said: ‘Louise had been grotesquely and cruelly injured, and her body defiled.’
She added: ‘Louise was particularly vulnerable because of her youth, lack of stable home and her anxiety and depression manifesting in self harm.
‘Even if Louise was rendered unconscious early in the attack by Shane Mays she would nevertheless have suffered intensely mentally and physically at his hands whilst conscious.’
She ruled as Mays was caring for her the relationship was ‘like a father and daughter relationship’.
‘That being so he committed the most gross abuse of trust,’ she said.
Louise was living with Mays and his wife Chazlynn at their one-bedroom flat in Ringwood House, Somborne Drive, in Leigh Park, after being thrown out of a relative’s home. She had lived with Mays and CJ previously in Montague Road, North End.
‘Crafty’ Mays, who has an IQ of 63, lured Louise to Havant Thicket where, by his own account, he repeatedly punched her face with both hands causing ‘catastrophic’ injuries.
He claimed to have instantly forgotten what he did, walking to his mother's home in Stratfield Gardens and saying he had taken Louise to Emsworth.
Mays said the same to his wife and Louise’s boyfriend Bradley Kercher, who he later tried to deflect blame upon.
Prosecutors say he secretly crept back and burned Louise’s body, which was found 13 days after the May 8 killing after a search involving 306 people, drones and dogs.
Reading a statement from Louise’s mother Ms Cooper today, prosecutor James Newton-Price QC, said: ‘This is any parent’s worst nightmare and now it's my nightmare.
‘This is one of the hardest, heartbreaking things I will ever have to do.
‘You have taken away a part of my heart which will never be replaced.
‘You killed my daughter Louise in such a traumatic way but then did what you did afterwards is beyond words - you are a monster - what gave you the right to do that?’
‘You have left that scarred in my mind for the rest of my life.’
She added: ‘You have turned my life upside down, I don’t sleep, eat, and my life is a mess. You did this to me, no-one else.
‘You came to my house the day you killed her, looked me in the eyes with no remorse when you knew what you had done was pure evil.
‘You made us relive what you did to Louise.
‘Louise will always live on through us, the memories locked away in our hearts.’
Ms Cooper said Louise one day hoped to be a mother, and was training to be a veterinary nurse.
She had already picked out a bridesmaid dress for the wedding between her mother and Richard O’Shea.
A statement from her father Bradley Smith said: ‘My family is in absolute turmoil and we will be for the rest of our lives.
‘My mental and physical health has also been affected with being unable to sleep as I’m tortured by nightmares and I miss my little girl enormously, constantly.
‘I honestly don’t think I will ever recover from this.
‘The best I can hope for is to cope better and I’m positive my family feel the same way. Louise was a beautiful daughter and I have been robbed of what was to be my time with her.’
Mr O’Shea said he sees his fiancee, Louise’s mother, ‘cry every night’.
‘What you have done has destroyed my life,’ he said. Mr O’Shea had been in Louise’s life for nine years.
Andrew Langdon QC said the murder was not planned and Louise did not suffer a ‘long period of physical suffering prior to death’.
Mr Langdon said the court ‘cannot be sure that this was a case that involves sexual or sadistic motivation’.
Mays, 30, of Somborne Drive, Leigh Park, denied murder.
He admitted manslaughter on the first day of his trial but ‘simply cannot face’ confessing the full brutality of his crime, the prosecution said.
A stick at the scene had DNA on it 38m times more likely to be Mays' DNA than anyone else, the court previously heard.
Blood spots on his white Adidas trainers were from Louise, a forensic expert said. He was spotted on CCTV walking to his mother’s home after the killing.
Louise lived her life on her phone. The last message sent from it was at 12.49pm that day.
By 3.11pm Mays was seen on CCTV in Swanmore Road walking by the entrance to Warren Park Primary School before going to his mother’s home.
READ NEXT: Recap coverage of the trial of Shane Mays
It comes as Hampshire County Council confirmed a learning review will be carried out following Louise's death.
As reported, the teenager had a social worker to whom she spoke the day before she was murdered by Mays.
The county council statement said: ‘All of the evidence heard in court will be considered alongside all other relevant information from the council and other agencies by the Hampshire Safeguarding Children Partnership in its learning review.’
Derek Benson, chair of the Hampshire Safeguarding Children Partnership, said reviews do not aim to ‘apportion blame’ and reports are anonymised.
He said: ‘Therefore, while I can confirm that a review is being undertaken, I cannot provide any further details, including providing an indication of when the review report will be published.’
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