A jealous boyfriend killed his own baby daughter, her mother and grandmother after torching their home on the day the child was released from hospital, a murder trial has heard today.

Carl Mills, 29, is accused of killing three  generations of the same family after setting their home ablaze.

Kayleigh Buckley, 17, six-month-old daughter Kimberley and grandmother Kim, 46, were all trapped in their home when it was engulfed in flames.

Newport Crown Court heard how Mills started  the fire after he became convinced Kayleigh had another man in her bedroom.

But the only people inside were the family –  who were celebrating Kimberley’s homecoming after being born prematurely at just  1lb 9ozs in hospital.

Neighbours saw Kayleigh banging on the  windows and screaming for help but they were unable to save her.

Prosecutor Greg Bull said: ‘The three victims  didn’t have a chance.’

He said they were unable to get down the  stairs because of where the fire was set.

He said: ‘Within minutes it became impossible  to save the people inside. Neighbours did all the right things but they were  confronted with a scene which can only be described as  heartbreaking.

‘Kayleigh was in the window of a smoke-filled  room crying for help for her and her baby.

‘People were calling out “Jump” but she  wouldn’t leave her baby. Neighbours could hear her saying she was on  fire.

‘Then within a few minutes there was silence.  All of the victims died in the fire.’

The court heard Mills (left) started the fire after he  became convinced Kayleigh (right) had another man in her bedroom

The court heard the only people in the house were  grandmother Kim (left, with granddaughter Kimberley), Kayleigh and the  six-month-old baby, who had just returned from hospital after being born  prematurely

The court heard how Kayleigh met Mills when  she was 15 on the internet – he was living in Manchester and travelled to her  home in Cwmbran, South Wales.

Mr Bull said: ‘He deliberately set out to  groom her sexually. Their relationship developed into a sexual one. He seemed to  exercise a magnetic control over Kayleigh.

‘Mills became obsessively jealous of  Kayleigh. He became obsessed she was involved with other boys.’

The court heard Kayleigh became pregnant with  twins born in March of last year.

Prosecutor Greg Bull said Mills became ‘obsessively  jealous of Kayleigh’ after they met on the internet

One twin, Angel, died at just two days after  being born weighing 15 oz but doctors were able to save Kimberley who weighed  1lb 9oz.

The baby was named after her gran who gave up  her job as an Avon lady to help raise her.

Mr Bull said: ‘Kayleigh started acting as a  mother and that was one of the factors which caused this violent  crime.

‘Mills didn’t want Kayleigh to spend more  time with the baby. He wanted Kayleigh to be with him and him alone. He become  convinced she was having an affair with another man.’

Mills was not invited to the homecoming of  baby Kim when she was allowed out of the Royal Gwent Hospital in  Newport.

The court heard he had been threatening and  controlling for months – and had been banned from the family  home.

But Mills wouldn’t leave Kayleigh alone and  was sleeping in a tent in front of the family home.

The family home was decorated with balloons  and banners for Kimberley – but the court heard Mills allegedly flew into a  rage.

The court heard texts were sent by Mills to  Kayleigh on the night before she died.

One said ‘I’ll burn your house down’, while  another read ‘I hope you f****** get burnt’.

Another text read ‘You lot made a mistake, a  very bad mistake,’ while a further text said ‘Sleep with one eye open you dirty  s***’.

The court heard Mills started the fire in the porchway  of the three-bed house

His fingerprints were found on a welcome home  banner which he had ripped down on the night of the fire in September last  year.

The court heard how he also sent a string of  messages taunting Kayleigh about the balloons outside the house – which the  prosecution claim places him at the scene.

In the messages he threatens Kayleigh who he  believes has another man in the house, saying he will cut off electricity to the  house, then set fire to it, the court heard.

He also explains how he wants to blow up the  oxygen cylinders there to help little Kimberly with her lung  problems.

The court heard how Kayleigh’s mother Kim (pictured) did  not like Mills but made efforts to include him in the family

Mr Bull told how Mills started the fire in  the porchway of the three-bed house – and the fire quickly  spread.

He said: ‘The fire extended rapidly and the  stairs were soon breached and the door gave way. It created a fireball into the  roof which burned down into the bedroom.

‘The house was well ablaze. The fire service  tried to enter but it was too ferocious. As this mayhem was developing, along  came Mills.

‘Neighbours were shocked by how calm he  appeared to be. He showed no emotion and did not attempt to rescue his daughter  or the woman he claimed to love.

‘It was the actions of a cold-hearted killer  who knew exactly what he was doing. He had carried out the threat he had made  hours earlier.’

Mills, of no fixed abode, denies three  charges of murder.

The court heard how Kayleigh’s mother  Kimberley did not like Mills but made efforts to include him in the  family.

Mr Bull said: ‘Kim was frightened of Mills  who she thought was unpredictable and threatening.

‘He had violent mood swings and often  threatened to do harm to them. Kim tried  to involve Mills but he became more controlling of Kayleigh. His behaviour was  abusive and irrational.’

The court heard how two weeks before the  murders, Mills had ‘trashed’ the family home while baby Kimberley was still in  hospital.

He was reported to police for criminal damage  while the family were out of their home in Cwmbran.

The court heard grandmother Kim was given  guardianship rights over the baby and Mills was not allowed to see her  unsupervised.

Mr Bull said: ‘Mills would not have access on  his own to the baby and this caused hatred and resentment to Kim and  Kayleigh.

‘There were threats to both of them by  setting their house on fire. Mills told Kim in a text message that he was going  to burn her from the earth.’

Mr Bull said the threats reached a peak on  the night baby Kimberley was due home.

The jury was told that Mills wouldn’t leave Kayleigh  (pictured) alone and was sleeping in a tent in front of the family  home

Mr Bull said: ‘It was meant to be a day of  great joy and celebration.’

But the court heard it became one of tragedy  after Mills repeatedly accused Kayleigh of having another man in the  house.

He said: ‘For a considerable period of hours  the text messages show Mills getting more and more frustrated by Kayleigh. He  was obsessive and jealous, assuming she was sleeping with someone  else.’

The court heard he repeatedly texted ‘Bring  him out’ before the arson attack at around 3.30am – just six hours after his  baby arrived home.

The trial continues.

Read more: DailyMail