A former fitness instructor who murdered his 18-month-old daughter just two weeks after adopting her with his husband has been jailed for life.

Matthew Scully-Hicks, 31, shook Elsie and may have banged her head against a hard surface after losing temper with the toddler at the couple's home in Cardiff.

His attack in May of last year caused "catastrophic injuries", with a pathologist saying they were "very typical" of a shaken baby. Her head had been "rocked backwards and forwards".

Scully-Hicks had claimed her daughter died after accidentally falling down the stairs, but he was found guilty by unanimous verdict at Cardiff Crown Court on Monday (6 November).

Sentencing him to a minimum of 18 years in prison on Tuesday, Mrs Justice Nicola Davies described how Scully-Hicks had become "frustrated" and "exasperated" by Elsie's crying.

"Elsie was aged just 18 months old when you killed her," Mrs Justice Davies told him. "A young, vulnerable and defenceless child."

She added: "This was a defendant who had – and much was made of it – regular access to health visitors, social workers. He could have disclosed that he was unable to cope. He could have said: 'I'm struggling.'"

Scully-Hicks showed no emotion as he was sentenced, Wales Online reported.

The jailing of Scully-Hicks is expected to be followed by a child practice review – the Welsh version of a serious case review – which will examine whether agencies failed to protect the toddler.

Elsie had been placed with Scully-Hicks and husband, Craig, in September 2015 by the Vale of Glamorgan council, having been removed from her drug-using mother.

Scully-Hicks cared for Elsie and her adopted sibling at the family's four-bedroom home in Llandaff, Cardiff, while Craig worked as an account manager.

During the four-week trial the jury was shown texts that saw Scully-Hicks complain about the toddler.

He described her as "Satan dressed in a babygro" and a "monster", adding that he was "ready to explode".

Part of one text read: "I'm going through hell with Elsie. Mealtimes and bedtimes are like my worst nightmare at the minute. She has been up there screaming for 10 minutes non-stop."

The court heard that neighbour Susan Bevan also heard the stay-at-home dad shout at the baby: "Shut up, shut up, shut the f*** up."

The case also uncovered a history of injuries suffered by Elsie during the eight months Scully-Hicks was her carer – all of which happened when she was alone with him.

Just two months after being placed in the home, Elsie was taken to hospital with a leg injury after what Scully-Hicks described as an accidental fall. An x-ray showed a fracture above her right ankle, but a second break in her right thighbone was missed, which could have prompted further questions about her care.

Elsie Scully-Hicks was attacked just 13 days after being formally adopted by Matthew Scully-Hicks

The following month, in December 2015, Elsie sustained a bruise to her forehead that Scully-Hicks claimed occurred when she pulled herself up on a toy kitchen.

The injured leg and bruise would have been seen by social workers, who attended the household every two weeks to check on how the adoption was going.

In January 2016, Elsie sustained another bruise to her head, but no alarm bells were raised and the toddler was allowed to keep living with the family.

A second hospital visit occurred in March 2016 when, according to Scully-Hicks, Elsie fell downstairs. She was kept under observation and discharged.

Despite the catalogue of injuries, the adoption was formally approved on 12 May 2016. Thirteen days later, Scully-Hicks dialled 999 claiming Elsie had fallen down the stairs again.

He told the operator: "She's not responding to me ... I didn't push the gate closed properly and she fell down."

She was taken to hospital with a bleed on the brain, a skull fracture, retinal bleeding in both of her eyes and damaged ribs. She died at the University Hospital of Wales four days later.

Prosecuting barrister Paul Lewis told Cardiff Crown Court that Elsie's death was "the tragic culmination of a course of violent conduct on [Scully-Hicks'] part towards a defenceless child".

He added that while Elsie should have been "loved and protected" she was instead "assaulted, abused and ultimately murdered".

Scully-Hicks' husband, Craig, told the jury he had not suspected anything was wrong in the family home and would have intervened had he thought so.

The review into Elsie's death is being launched by the Cardiff and Vale Regional Child Safeguarding Board and could take up to a year to complete.

David Niven, chairman of two safeguarding children boards in England, and former head of the British Association of Social Workers, called the case "rogue".

"Everybody will want to know what happened and what could've been done to stop it," he told the BBC.

"Similar to other serious case reviews, all of the agencies involved will be looked at by an independent author that will be commissioned externally and will take people through the sequence of events of what happened.

"What this review is all about is looking at how people work together in partnership or possibly didn't work together in partnership, and missed things possibly that should've been found."