A taxi driver only confessed to murdering a prostitute because a senior detective threatened his daughter, a court heard.
Christopher Halliwell, 52, admitted he took Becky Godden, 20, from the streets of Swindon, had sex with her and strangled her before burying her body in a remote field more than a decade ago.
But he is now denying her murder and told Bristol Crown Court why he told Detective Superintendent Steve Fulcher about killing Miss Godden after he had been arrested on suspicion of kidnapping missing office worker Sian O'Callaghan in March 2011.
The father-of-three told the jury he was dropping Mr Fulcher, who was leading the investigation for Miss O'Callaghan, in it because the officer had made threats against his daughter.
"I was dropping him in it. With the level of detail I was giving I should have been arrested and cautioned. I knew once I got to the police station he was in trouble," he insisted.
"It had nothing to do with being refused a solicitor or taken to the police station because he threatened my kids.
"He threatened one of my daughters. Had he carried out that threat it would have had an effect on my two other kids.
"I was in the crap anyway because I was aware I was going to be arrested for murder and I had been arrested for kidnap and I knew that was going to change to murder.
"In layman's terms I was in the shit anyway and I couldn't drop myself in the shit any deeper."
Prosecutor Nicholas Haggan QC asked Halliwell to reveal details of the threat he claims Mr Fulcher made but he refused, telling the jury: "I wouldn't embarrass one of my girls."
Halliwell accepted he "loathed" Mr Fulcher and confirmed that during his cross-examination of the former Wiltshire officer last week he had called him a "corrupt bastard".
But he denied that he blamed Mr Fulcher for the situation he now finds himself in, telling the jury: "It wasn't a true account, it was a lie. If I had been responsible it would have been a confession.
"The more I lied to him the more I could see that he wasn't seeing me as a suspect, he was seeing me as a promotion, adulation, another plastic trophy in his cabinet."
The court heard that Halliwell was arrested on the morning of March 24 2011 at an Asda supermarket in Swindon and an "urgent interview" was carried out by two detectives, with Halliwell revealing nothing about Miss O'Callaghan's disappearance.
He was later driven to the rural Barbury Castle location where he spoke with Mr Fulcher and directed him to Uffington in Oxfordshire where Miss O'Callaghan's body was found.
Halliwell then took the detective to a field in Eastleach, Gloucestershire where he said he had buried Miss Godden.
He was then taken to a police station in Swindon and spoke to a solicitor before giving a "no comment" interview to the police.
Mr Haggan asked Halliwell why he did not say anything to the officers once he was interviewed at the police station.
Halliwell replied: "If I had spoken then Fulcher wouldn't have faced a disciplinary, would he? That's what it all comes down to. What he did was very wrong.
"After a particular police officer threatened my daughter. At the end of the lawful urgent interview if I had been taken to the station I would have spoken once I had a solicitor."
Mr Haggan asked why Halliwell had put the O'Callaghan family through the ordeal of pleading not guilty to murder and only finally admitting his guilt nearly 18 months after she died.
"You couldn't care less about anyone but yourself," the prosecutor said.
Halliwell told the court: "I do care, I am a father myself. What I put that family through was horrendous, I said that many times.
"I pleaded guilty once I found out Fulcher was deeply in the mire."
Mr Haggan replied: "He wasn't. They found he acted in good faith throughout with the intention of finding Sian. He was given a final written warning, his career wasn't ruined."
Mr Fulcher now works as a consultant in Somalia after leaving Wiltshire Police.
Halliwell, formerly of Ashbury Avenue, Swindon, Wiltshire, denies a single charge of murder.
Halliwell said a shovel, which the prosecution alleges was used to bury Miss Godden's body, and that was recovered from his shed when he was arrested in 2011 was not his.
The jury has previously heard that the soil recovered from the shovel was likely to have come from a field where the remains of Miss Godden were found.
Forensic experts were also able to match tape found in Miss Godden's grave to tape attached to the shovel in Halliwell's shed.
Halliwell told the court that the shovel did not belong to him and it was already in the shed when he moved in with Heather Widdowson in 2005.
"They are scrap, you can't use them," he said.
Mr Haggan rejected this and told the court: "The shovel is yours - it came from your shed. You used that implement to dig Rebecca Godden's grave.
"The reason her grave was shallow is that you had the wrong implement and that the ground is very hard."
Halliwell replied: "I was not responsible for burying Rebecca."
Mr Haggan told the defendant: "When you were arrested for Sian's murder you knew the game was up and you decided to unburden yourself and that's what you did.
"You made up a cock and bull story to try and escape a whole life term."
Halliwell replied: "I don't care about a whole life term."
Mr Haggan, in a closing speech for the prosecution, said Halliwell had "lied time and time and time again" during his evidence.
He described the taxi driver as "smug" and highlighted similarities between the murders of Miss O'Callaghan and Miss Godden.
The prosecutor said both women were young, attractive with a slight build and disappeared from Swindon in the early hours of the morning.
Both women were strangled and their bodies were deposited in rural locations close to each other, the court heard.
"The defendant did as he had confessed," Mr Haggan told the jury of six women and six men.
"He took Rebecca from the streets of Swindon. He strangled her. He had sex with her. He buried her in Oxo Bottom field.
"He murdered her. He is guilty. All that he has told you about the drug dealers and the bag is a fairytale."
Mr Haggan added that there was not "a shred of doubt, not even a slither" that Halliwell was guilty.