A man killed his 17-year-old step-daughter to “prevent her pursuing her allegations of sexual abuse against him,” prosecutors said.
Scott Walker killed Bernadette Walker, who was known as Bea, after she told her mother he had been abusing her.
Diary entries reveal the teenager had not been believed. Instead, her mother conspired with Walker to cover up the killing, Cambridge Crown Court heard.
In an undated entry, Bea wrote: “Told my mum about my dad and the abuse. She called me a liar and threatened to kill me if I told the police.”
Bea’s body has never been found despite multiple searches and it is thought Walker, 51, disposed of her body in countryside near Peterborough.
Bea also wrote that she would block her parents out of her life after she left home, adding: “I’d rather say I’m an orphan than say I have abusive parents who couldn’t give a s*** about me or what happens to me.”
After Bea’s death, Walker formed “an unholy alliance” with her mother Sarah Walker, 38, to cover up the murder, prosecuting QC Lisa Wilding said.
Using Bea’s phone, Sarah Walker hacked into her daughter’s social media and email accounts immediately after speaking with Walker on 18 July, 2020, the day of the murder.
She changed Bea’s passwords and sent messages to herself from Bea’s phone, apologising for the abuse allegations.
She also messaged Bea’s friends to say she had run away because she had lied, later telling police that Scott Walker had told her to send these fake messages.
Later on the night of Bea’s murder, the couple drove to a lock-up garage where the prosecution believe Bea’s possessions and mobile telephone may have been stored.
Scott Walker went back and forth from the garage that night and over the next two days.
Sarah Walker went with him on some of those trips, including to outlying areas of Peterborough and beyond, with police piecing together their movements from mobile phone, CCTV and number plate recognition data.
Nicola Rice, senior prosecutor from CPS East of England, said that the couple then “concocted a plan and began to lay a false trail that she was missing.”
“They went to extraordinary levels of deceit to cover-up what happened, telling a web of lies to family members, friends and ultimately to the police,” she said.
The pair did not report their daughter missing until 21 July. They were arrested six weeks later.
Sarah Walker admitted two counts of perverting the course of justice by sending messages from Bea's phone after she disappeared and by providing false information to the police relating to her disappearance, with Scott Walker telling the court that his partner had feared the involvement of social services.
Bea’s friends also gave evidence at the trial, with some saying it was unusual for her not to post on social media after 17 July.
Rice added: “The delay in reporting Bea missing and the lies they told everyone were nothing short of wicked and designed only to protect themselves without any thought, care or love for Bea or their wider family.”
Both Scott and Sarah Walker will be sentenced on 10 September.
Separately, a watchdog has ruled that a police officer had “no case to answer for misconduct” over his role in Bea’s missing person investigation.
The Independent Office for Police Conduct (IOPC) said it launched an investigation in October last year after the conduct of the officer was referred to it by Cambridgeshire Police.
On Monday, the IOPC said the officer’s performance had been “satisfactory” and it had “identified a number of potential areas of learning for the force.”