The astonishing lengths fentanyl killer Luke D'Wit went to in order to 'brainwash' Essex couple
He portrayed himself as an "upstanding, kind member of the community", but in reality, he was a cold, calculating killer - described by police as one of the "most dangerous men" they had ever come across.
Luke D'Wit is now coming to terms with the fact that he will spend at least 37 years behind bars - little comfort for the family of Stephen and Carol Baxter, the married couple he spent years manipulating, before poisoning with lethal doses of the opioid painkiller fentanyl.
The deaths of the Baxters last April was the culmination of a relentless campaign of deceit, with D'Wit going to remarkable lengths to gain their trust.
His elaborate plot involved false identities, fake wills and deadly medication - all part of a sinister plan which saw the Baxters become "dolls in his dollhouse", according to their son Harry.
But how did he do it?
As D'Wit begins his double life sentence, we look back at some of the most shocking details to emerge in court of the cast of characters the killer created, and the tactics he deployed.
'Andrea Bowden' - the fake US-based doctor
D'Wit first met the Baxters between 2012 and 2013 to help build a website for their shower mat business and gradually started to infiltrate their lives.
So when he discovered that Mrs Baxter was suffering from the thyroid condition, Hashimoto's disease, he saw an opportunity - creating more than 20 false personas to manipulate her, using 80 electronic devices.
One of those was a fake Florida-based doctor called Dr Andrea Bowden.
D'Wit sent a series of emails to the Baxters purporting to be Dr Bowden, encouraging them to drink boiling water, lemon and aspirin tablets to improve their liver health - a way of creating a “concoction [D’Wit] could put something into to kill them off”, according to prosecutors.
He also pretended to be fellow Hashimoto's sufferers to back-up his lies, constantly providing Mrs Baxter with advice that had "no clinical basis".
'Jenny' - the theatre producer with a big promise
Listen to D'Wit pretending to be 'Jenny'
It wasn't just Mrs Baxter that D'Wit targeted - he also went to great lengths to keep her family on side.
One of the most astonishing moments during the trial was when jurors were played audio of D'Wit practising a female voice for another of his fake identities.
D'Wit deceived Mrs Baxter into believing that one of her fellow Hashimoto's sufferers had a sister called Jenny - a theatre producer who could help the Baxters' daughter Ellie with her career as a vocalist.
'Jenny' asked Ms Baxter to send her recordings of herself singing, which she then recorded at her parents' house with the help of D’Wit.
When her parents died, D'Wit even sent a text message to Ms Baxter pretending to be Jenny in which he wrote: “Oh no my darling sweetheart, I’m so sorry”.
'Horrible smoothies'
Having successfully gained their trust, D'Wit then set about giving Mrs Baxter smoothies which she believed were helping with her condition.
Unbeknown to her, they were actually making things worse - allowing D'Wit to ply her with a cocktail of drugs that were masked by the flavours of lemon and turmeric.
Sentencing D'Wit, the judge at Chelmsford Crown Court said that the fentanyl had been crushed into a powder and given to the couple in these drinks.
Describing the smoothies in court, Mrs Baxter's daughter Ellie said that they "tasted gross" but believed her mother "just got a bit desperate”.
As well as making the smoothies, D'Wit also gave Mrs Baxter her medication in the mornings and evenings and was round the house "every day".
'Our dear friend Luke'
D'Wit wasted no time in moving to the next stage of his plan, drawing up a fake will just a day after the Baxters were found dead.
He made the will on his phone, making himself the beneficiary and inheritor of the couple's shower mat firm Cazsplash.
He also referred to himself as their "dear friend Luke D'Wit" who would become "director and person with significant control".
It was to play a crucial part in his downfall.
During searches, police found the will – which was not the long-held document held by the Baxter's solicitors – as well as used fentanyl patches.
Key pieces of evidence then led to D'Wit being arrested in July and subsequently charged with two counts of murder.
'Driven by desire to control'
Watch officers speak to D'Wit shortly after discovering the bodies of Carol and Stephen Baxter
Besides the obvious financial gain, the judge sentencing D'Wit said that it was his belief that it was actually a "desire for control" that was the principal motivation behind the "cruel and senseless" killings.
D'Wit thrived on having the power to decide whether "another person lives or dies", Mr Justice Nicholas Lavender concluded, before adding that it was this that gave him the "ultimate form of control".
D'Wit had "lied his way into our lives”, daughter Ellie Baxter said - exploiting her parents' kind nature which led to them "taking him under their wing" after D'Wit's father died.
In return, D'Wit "completely brainwashed" them in what prosecutors summed up as the most "extraordinary long-term case of manipulation”.
After the jury returned two guilty verdicts, police described D'Wit as one of the most dangerous criminals they had ever faced - with the senior investigating officer left in no doubt that had he not been stopped, D'Wit would have gone on to kill again.
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