Becky Watts murder jury told 'ignorance a ridiculous concept'

Nathan Matthews and Shauna Hoare (right) are accused of murdering Becky Watts (left)

Any claims the woman accused of Becky Watts' murder was ignorant of the teenager's gruesome death are a "ridiculous concept", a jury has heard.

Body parts belonging to the 16-year-old were found in a garden shed several days after she vanished from her family home in St George, Bristol.

Nathan Matthews, 28, and his girlfriend Shauna Hoare, 21, deny murdering her.

He admits the manslaughter of his stepsister, but insists Miss Hoare had no part in it, the court was told.

Prosecutor William Mousley QC said the accused had denied hatching a plot with Miss Hoare to murder the teenager.

Mr Mousley argued Becky's death was "no accident".

He described the "the ridiculous concept that she [Ms Hoare] was in blissful ignorance of everything that was going on during that period of time".

The accused appeared "genuinely concerned" that Becky was missing, a police officer said

The Bristol Crown Court trial heard Mr Matthews had strangled the teenager after trying to kidnap her.

Mr Mousley told the jury the defendant admitted killing Becky and storing her body parts at another address.

The trial heard how Mr Matthews, when arrested, told police he alone packed Becky's body into the car without his girlfriend knowing.

He told police when Miss Hoare had gone to bed, he took the body into their house and over the coming days dismembered it with a circular power saw and wrapped the various parts in plastic bags.

The first witnesses: Jon Kay, BBC News, in court

• A neighbour of Miss Hoare and Mr Matthews described hearing banging, slamming doors and a noise "like something very heavy" being moved across a wooden floor

• Christopher May, who calls Mr Matthews his "step grandson", told the jury he did not see anything "not normal" in Mr Matthews and Miss Hoare's relationship

• The jury were played a phone call of police asking them to return home so their house could be searched for Becky

• The phone line is bad. The couple say they are in the car on their way to a night out. Miss Hoare asks if the house search can be done the next day instead

Becky's boyfriend Luke Oberhansli, 18, told the court he last saw her on 17 February and had been in contact until 19 February - the day of the alleged murder - when some of his texts failed to deliver. He went to her house.

The jury heard Miss Hoare came to the door and he asked if Becky was there. Miss Hoare and stepmother Anjie Galsworthy said they did not know and looked in her bedroom with no success.

Becky seemed happy "on a day to day basis", her boyfriend told the court

Prosecutor William Mousley QC said Mr Matthews and Miss Hoare were working as a team

Prosecutors allege that by this time Becky was already dead.

Another witness, PC Lamorna Trahair, told the court she visited 18 Crown Hill in response to the call that Becky was missing.

She said there was "no behaviour displayed by anyone present at the address which heightened any concerns about Rebecca".

Her colleague Det Con Clare French, who was part of the missing persons inquiry, told the jury she later interviewed Mr Matthews for about 10 minutes about his relationship with Becky and where he had last seen her.

She told the jury she asked him if he got on with Becky and he replied "he did and he didn't".

Charges denied

Mr Matthews, of Hazelbury Drive in Warmley, South Gloucestershire, has pleaded guilty to perverting the course of justice, preventing the lawful burial of a corpse and possessing a prohibited weapon, but denies conspiracy to kidnap.

Miss Hoare, of Cotton Mill Lane in Bristol, is charged with conspiracy to kidnap, perverting the course of justice, preventing the lawful burial of a corpse and possessing a prohibited weapon. She denies all counts.

Two other men on trial - Donovan Demetrius, 29, of Marsh Lane, Redfield, Bristol, and James Ireland, 23, of Richmond Villas, Avonmouth - each deny a charge of assisting an offender.

Karl Demetrius, 29, and his girlfriend Jaydene Parsons, 23, both of Barton Court, Bristol, previously pleaded guilty to assisting an offender after Becky's body was found in their garden shed.

However, both said they were unaware of what the packages actually contained.

The trial is expected to last six weeks.