Police tapes have revealed the cold-hearted smirks of schoolgirl Becky Watts’ killers as they lied about her horrific murder.
Nathan Matthews, 30, was jailed for a minimum of 33 years for murdering his stepsister, while his girlfriend Shauna Hoare, 23, is currently serving 17 years for manslaughter.
The youngster was suffocated and her body was then chopped into pieces and discovered in a garden shed 11 days later. Becky suffered more than 40 injuries before being suffocated by Matthews.
A new documentary hosted by Susanna Reid, airing on ITV tonight, examines how the detectives investigating the case came to realise Matthews and Hoare were responsible for her death.
It explores how forensic evidence and intense police interrogation led to them being caught.
During their first interview after Becky disappeared from her home, Hoare was ‘giggly’
Matthews appeared unconcerned by his stepsister’s disappearance in his police interview
The schoolgirl disappeared without trace from her home in Bristol in March 2015.
Police discovered the couple were the last people to see her before she went missing.
During their first interview Hoare was ‘giggly’ while Matthews appeared unconcerned by his stepsister’s disappearance.
They said they heard the front door slam in the house and thought Becky had gone out earlier in the day.
Richard Ocone, Detective Chief Inspector, said: ‘They were really consistent in their accounts, however the detective’s side of my brain was saying that they fit together really conveniently and neatly.
‘Even the best witnesses will provide accounts that are incorrect.’
The youngster was suffocated and her body was then chopped into pieces and discovered in a garden shed 11 days later
At Becky’s house, the forensic team found a key clue.
Jon Draper from the team said: ‘That’s when we came across what appeared to be blood or red staining on the architrave of the doorframe leading into Becky’s room.’
When a fingerprint in the blood turned out to belong to Matthews, the pair were arrested, initially on suspicion of kidnap.
Becky’s grandmother Pat said: ‘If was going to be something bad, it didn’t surprise me. Nathan hated Becky and made it obvious.’
Detectives didn’t tell Matthews they now knew it was his fingerprint in Becky’s blood, but hinted at what they’d found, to increase his unease.
Det Con Marie Stephen explained: ‘Without giving that to them on a plate, if you like, it leaves them having to think about it, and puts them under more pressure.’
Police searched the pair’s own house, finding that despite the fact it was filthy and crammed full of furniture, the bath was sparkling clean.
The search also uncovered incriminating receipts which indicated a gruesome truth.
DCI Ocone said: ‘Those receipts indicated that somebody on the Friday, when Becky was reported missing, had been to B&Q and had bought a circular saw, some gloves, goggles, and a face mask… Does it really mean he has tried to dismember a body?’
The investigation then turned into a murder inquiry.
Becky’s stepbrother Nathan Matthews (left), 30, and his girlfriend Shauna Hoare (right), 23, were jailed for a total of 50 years and have since lost challenges against their convictions
Detectives withheld the receipts find from Matthews, increasing the pressure by saying his home had been forensically searched.
DCI Ocone said: ‘I think it probably felt like he was battling against a rising tide, and actually, you could feel the evidence starting to come on top, and actually it was starting to weigh quite heavily.’
Matthews then confessed in a prepared statement that he’d used the circular saw to dismember Becky’s body in the bath.
He admitted wrapping up the body parts and hiding them in a shed a few hundred metres from his home.
DCI Ocone admitted that nothing prepared him for what they found there: ‘The nature of the find is horrific and shocking, I have never dealt with anything like this. And it will stay with me throughout my service, it will stay with me probably throughout my life.’
With Matthews claiming sole culpability, detectives couldn’t yet link Hoare to the murder.
She was initially charged with perverting the course of justice, before a series of deleted texts were recovered from one of her phones.
They revealed a disturbing motivation behind the murder – text messages between the pair talking about abducting young girls, taking them home and putting them in their loft.
DCI Ocone said: ‘I think they showed that Shauna’s involvement was far tighter, far closer to actually what had happened… It suggested that she had been involved in the dismemberment and the packaging of Becky, after she’d been killed.
During their trial, Bristol Crown Court heard they targeted Becky due to their dislike of her and a shared sexual interest in petite teenage girls.
Matthews was jailed for life for murder with a minimum of 33 years while Hoare was convicted of manslaughter and jailed for 17 years.
In June they both had an appeal against their sentences and convictions thrown out of court.
Elsewhere in the documentary Becky’s father Darren Galsworthy said he could still see where his 16-year-old daughter had been decapitated after she was kidnapped in a sexually-motivated plot in Bristol.
Mr Galsworthy said: ‘When we saw her in the morgue, that’s when it really hit us.
‘I mean, they did their best to cover up where he cut her up and things like that. But I could still see where he’d decapitated her. And no parent should have to see that.’
The Murder Of Becky Watts: Police Tapes will be on ITV tonight at 9pm