How Sixth Commandment killer Ben Field was caught by police

The detective sergeant and his colleagues had spent months painstakingly building the case against Field, whose sickening crimes are the subject of BBC hit drama The Sixth Commandment.

But when he saw him for the first time, Mr Earl’s first thought was that Field seemed ‘small’.

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“This was someone I felt I knew a lot about.

"I’d read all his written work, I’d been through his phones, his computer, everything,” said the detective, who was the 'officer in the case' during the trial at Oxford Crown Court in 2019 and who in the Sixth Commandment is played by Gangs of London actor James Harkness.

“I think you possibly build someone up in your imagination, don’t you. But he seemed small to me.

“That’s the only way I can describe him; he seemed small.

“Just insignificant. He was a disappointment.

“This was someone who’d manipulated umpteen people, had committed some awful crimes, was very intelligent and I was just disappointed, actually, when I charged him.”

For months, his working life had been consumed by the case.

“You think about the case in the shower in the morning, you think about the case when you’re driving home,” he said.

“Everything was Ben Field, Ben Field. Then when I finally got to charge him, [it was like] ‘is that all you’ve got?’”

Ben Field (right), and the actor - Eanna Hardwicke - playing him in Sixth Commandment Picture: BBC/TVP (Image: BBC, TVP)

Mr Earl, who during his eight years on Thames Valley Police’s major crime team also helped bring Oxford’s ‘Wind in the Willows killer’ Michael Danaher to justice, had only just returned from paternity leave when another officer contacted him in early 2017 asking for advice about taking a blood sample from someone in hospital.

That hospital patient was Ann Moore-Martin, who Field would later admit defrauding out of thousands of pounds.

“The officer said [they] thought she may be being poisoned to get her money,” Mr Earl said. “That doesn’t happen, really.”

When the investigation came to the force’s major crime team a few weeks later, the sergeant asked his boss, Mark Glover, if he could be assigned to the probe.

At that stage – early summer 2017 – there was little indication that this would become a two year investigation, involving scores of police officers and thousands of hours’ worth of work.

Mr Earl said: “It wasn’t really until we delved into what material we’d already secured that we started seeing how big it was going to be.”

Ben Field, the killer

The son of a Baptist minister, Field met university lecturer Peter Farquhar when he was a student at the University of Buckingham in 2011.

Mr Farquhar had a wide circle of friends, and had penned four novels after retiring from teaching at public school Stowe in 2004.

But he was lonely and craving affection.

Heterosexual Field saw his opportunity. He embarked on a relationship with his lecturer and moved into his home in Manor Park, Maids Moreton, in November 2013.

Field proposed on Mr Farquhar’s 68th birthday in January 2014. “Gone are the fears of dying alone,” Mr Farquhar wrote after his betrothal to Field later that year, describing it as ‘one of the happiest moments of my life’.

Peter Farquhar and Ben Field at their betrothal ceremony Picture: TVP/PA Media (Image: Thames Valley Police/PA Media)

The younger man learned in November 2014 that his partner had changed his will so he would inherit the house and get £15,000; but only if Field had lived there for two years before Mr Farquhar's death.

He began secretly drugging and gaslighting Mr Farquhar, with a judge at Oxford Crown Court later concluding that the killer had ‘enjoyed the cruelty of it’.

Field fed his older partner a psychoactive drug, BK2CB, at an event to launch one of Mr Farquhar’s own books at Stowe School.

He was humiliated, seen by his friends slumped over a table, struggling to sign his books.

By mid-September 2015, Mr Farquhar had changed his will again, leaving Field £20,000 and giving him the right to live in the Manor Park property for life.

“You were now free to kill him whenever you chose to do so,” judge Mr Justice Sweeney would tell the murderer in 2019.

An aerial view of Manor Park in Maids Moreton, Buckinghamshire, of the former homes of Peter Farquhar (left) and Ann Moore-Martin (Steve Parsons/PA) (Image: Steve Parsons/PA Media)

His ploy appeared to have worked. At the time, Mr Farquhar’s death in October 2015 was put down to natural causes.

He was thought to have drunk himself to death, while Field was paid £142,000 when the Manor Park property was sold in December 2016.

It was not until police started investigating concerns raised by Ann Moore-Martin’s niece in early 2017 about Field taking her aunt’s money that detectives followed the trail that led them back to Mr Farquhar.

Follow the money

“We started to look at the sequence along that road in Manor Park,” detective Mr Earl said.

Miss Moore-Martin, a retired Bicester headteacher with whom Field was in a romantic relationship within a month of Peter's death, lived at one end of the road. Mr Farquhar was at the other.

In between, lived another elderly couple whose house Field would later admit burgling.

DS Earl said: “As we built the picture around Ben Field we became more concerned about his activity.

“This is a youngish man who’s a university student. But he’s working at a care home, he’s lodging with various elderly people.

“Then we did the financial work and found he’d benefitted from Peter’s will.

"That was the catalyst to say hang on a minute, this isn’t normal for someone to be benefitting from the wills of two elderly people in quite quick succession, one of whom has died.”

The police began to dig into the circumstances of Peter Farquhar’s death.

The more they looked into his death in 2015, the stronger their suspicion became that he had been poisoned.

They applied to exhume the academic’s body. “We do it once a decade or so in the force. It’s very, very unusual to the point where hardly anyone serving knew what to do and the processes to go through,” Mr Earl said.

Samples of his hair were sent to France for testing, with the officers using Field’s own journals and Mr Farquhar’s description of his symptoms to narrow down the drugs they wanted the forensic scientists to test for.

“We knew we’d need his hair,” DS Earl said. “That would give us the long-term picture of his health and the toxicology.

“He was such a fit man, he was such an active man, he had a very full social life. Then, suddenly, he started hallucinating and seeing insects crawling all over his bathroom.”

The officer said: “We came up with a list of drugs, sent that off and when it came back with the results [it] matched perfectly with Peter’s symptoms and Field’s written records. That was a highlight.”

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The police had a theory, the toxicological results suggested they were right.

Next, they needed to piece together how Field might have killed his older lover.

“The challenge was proving that he had killed Peter on October 25,” Mr Earl said.

“That was really difficult because we had no scene, the toxicology we had was for the most part long-term so it didn’t give us the picture on the night of Peter’s death and the mechanism by which he did it wasn’t, at the outset, completely clear.

“So, we had an elevated level of alcohol in Peter’s system, we had evidence of sleeping tablets in his system.”

But at that stage the police were unable to say how he swallowed the alcohol or took the drugs.

At his trial, Field would tell the jury that Mr Farquhar could have died from drinking whisky and taking his usual dose of insomnia drug flurazepam.

“This murder never happened. No one killed anyone,” Field said from the witness box.

“In effect, we had to re-create the events of that evening in finite detail,” detective Richard Earl told the Oxford Mail.

“One of the most important ways we did that was to recreate the scene.

“If there’s a stabbing in central Oxford and we have a body on the ground, our experts from headquarters can go there, they can scan the scene, they can film it with drones, they can photograph it and we can rebuild the picture.”

Two years on from Peter Farquhar’s death, the major crime team detectives had no murder scene and the property where it happened had been extensively remodelled.

All they had was a few seconds of footage from the body-worn video camera of a police officer called to reports of the death, sweeping across the living room.

From those nine seconds, a member of the Thames Valley squad painstakingly recreated the room as it would have been on the date of Mr Farquhar’s death.

Using a computer programme, they drew every piece of furniture, every picture on the wall. In short, they drew everything.

Why? Because the detectives wanted to prove beyond reasonable doubt that the victim was not watching television, that he was sitting opposite Field’s armchair, that Field – whose phone records put him at the house on the night of the murder – had handled his victim’s glass.

There were other important pieces of evidence, including the killer’s own extensive writings in journals and diaries.

Among them was what the prosecution said was a plan of how he would kill Mr Farquhar. “He said – incredibly – that he wrote it after Peter’s death, despite the fact it was dated before his death,” Mr Earl said.

And there were other crumbs left by Field.

He had photographed himself with messages written in a bathroom mirror for Ann Moore-Martin to find - purporting to be from God, they included one that read ‘Ben loves you’.

In his journals, he had drawn up a list of ‘100 clients’, including his parents and grandparents, which prosecutors said was a tally of future targets although which Field claimed were people who ‘may be useful’ to him.

Field photographed himself with the messages he was leaving for Miss Moore-Martin Picture: TVP/PA Media (Image: Thames Valley Police, PA Media)

The evidence was distilled into a timeline, pulling together hundreds of different strands into one place.

“That document was our bible, which we went through line by line,” Mr Earl said.

“The complexity of the case was to interweave what Peter had written about his deteriorating health alongside what Ben Field was writing about his machinations at the time.

"That was interspersed with the factual evidence we could recover from other sources.

“It was only when you overlaid all the different pieces of evidence that you could put together a full picture of what was happening.

“We did such a good job on that he pleaded guilty to almost everything. He pleaded to all the frauds, the burglaries.

“That was a real highlight of the investigation to get those guilty pleas because it just seemed so unbelievable.”

From the witness box, Field accepted drugging Mr Farquhar, claiming that it was because the older man woke him up by being active around the house at night.

He admitted entering ‘fake’ relationships with both Mr Farquhar and Miss Moore-Martin in order to benefit financially from their deaths.

Field told the jury: “The mirror writing was all fake, the relationship was all fake and done with gain in mind.

“I have deceived absolutely everybody that I have any kind of relationship with.”

The jury spent 77 hours deliberating on their verdicts.

Mr Earl, who having begun the investigation after the birth of his second child found out during the trial that he and his wife were expecting their third, felt ‘definite relief’ when the panel of 12 found Field guilty of Mr Farquhar’s murder – although he was acquitted of attempting to murder Miss Moore-Martin.

Peter Farquhar was murdered by Ben Field (Image: Thames Valley Police/PA Media)

Usually, the officer of 20 years finds it does not help to empathise with an individual who has been murdered.

This case was different.

Mr Earl said: “I feel a real affinity with Peter. We have a lot of the same interests; I think we’d have got on quite well. We have similar personalities in some ways.

“To understand Peter was to understand why he died. I did feel maybe I’d done my bit for him.”

He added: “This case, for me, was almost the end of an era.

“It was the last old-fashioned murder investigation. There was very little digital media, there wasn’t much phone work, there was no CCTV.

“It was what I’d call old-fashioned coppering; that laborious, painstaking analysis and review of written material and small pieces of evidence.”

Commendations

In April this year, six years after the initial report, Thames Valley Police’s chief constable Jason Hogg awarded official commendations to 16 officers and civilian investigators involved in bringing Field to justice.

But there were at least 100 police officers and staff members involved in the investigation, not to mention the lawyers who saw the case through the courts.

Mr Earl said: “It’s really hard to stress how big this investigation was and how much work went into it.

“Although there have been various documentaries, press releases and podcasts, I don’t think any of them could grasp the volume of material we had to look at.”

DS Richard Earl and Chief Constable Jason Hogg earlier this year Picture: TVP (Image: Thames Valley Police)

Detectives had looked ‘very carefully’ at Field’s past but found no evidence he was responsible for other murders.

“If he hadn’t been caught I think he would have just carried on. I don’t think he would have stopped,” Mr Earl said.

“He said in the trial he had manipulated everyone he’d ever met; his own parents, his friends, his girlfriends, everybody.

“I think he got away with it pretty easily with Peter; he was never challenged. He would have got away with it, I think, with Ann had she died a couple of weeks earlier, before the police got involved.

“And I think he would have kept going, manipulating people any time he needed money.”

Field, who was given a mandatory life sentence in 2019, must serve at least 36 years in custody before he is eligible for release.

He has already lost one appeal against conviction, although the Criminal Cases Review Commission confirmed in July that they had been asked to look into the case with a view to referring Field's murder conviction back to the Court of Appeal. 

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