Becky Watts case: Teen 'strangled when kidnap scare plan went wrong'

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

A man accused of murdering Becky Watts said he planned to "scare" her by putting her in a suitcase and putting tape around her mouth, a court heard.

Nathan Matthews, 28, told police he went to Becky's house to "teach her a lesson" but his "face mask slipped", and he "panicked" then "strangled her".

Bristol Crown Court heard he described himself in an earlier police interview as "psychologically disturbed".

Mr Matthews and Ms Hoare, 21, deny murdering the 16-year-old.

Becky went missing on 19 February. Body parts were later found at an address in Barton Court.

In a statement after his arrest on 2 March on suspicion of murder he said: "Shauna did not know anything about my causing the death of Rebecca or my attempt to dispose of the body."

Mr Matthews said he had gone to Becky's family home at 18 Crown Hill to return a tin to his grandmother, but had taken "a bag, a stun device, handcuffs, tape and a mask".

He said he had developed an idea to scare Becky by kidnapping her to teach her a lesson.

The court heard he said: "I believed she was selfish and her behaviour towards my mother was a risk to her health."

The jury was told that before Mr Matthews' statement was read, he said: "Do I have to listen to it or can I put my fingers in my ears?"

He said Ms Hoare had gone into the garden on arrival and he had gone back to the car and got the bag and other items.

'Similar to a caveman'

In his statement, he said he took everything upstairs, knocked on Becky's door and when she opened it he was wearing a mask and "used the items I had to subdue Rebecca".

"During a short struggle, my mask slipped and Rebecca was able to see my face."

He said he panicked and strangled her - put her into the bag and took everything downstairs and put it in the boot of his car.

In an earlier police interview conducted on 28 February when he was arrested on suspicion of kidnapping his stepsister the court heard Mr Matthews described himself as "emotionally unstable and psychologically disturbed".

In it he said: "When I'm aggressive, I'm similar to a caveman.

"It's like an instinct, I will react."

Mr Matthews, 28, of Hazelbury Drive, Warmley, South Gloucestershire, admits killing his stepsister but denies murder and conspiring to kidnap her.

He also admits perverting the course of justice, preventing Becky's burial and possessing a prohibited weapon.

Miss Hoare, 21, of Cotton Mill Lane, Bristol, denies murder and conspiracy to kidnap, the weapons charge, perverting the course of justice and preventing a burial.

Two other men, Donovan Demetrius, 29, and James Ireland, 23, deny assisting an offender.

The trial continues.