Police are reviewing claims that a double killer who used fentanyl to poison a retiring couple to try and gain control of their company may have killed his own father and grandfather and remained undetected for years.
Stephen and Carol Baxter were found dead at their home in West Mersea in Essex by their daughter Ellie on Easter Sunday last year.
The couple had been planning on retiring after decades of hard work establishing a successful company in the South East of England.
An Essex Police spokesperson said: “Up to the conviction and sentence of Luke D’Wit, our determined focus has been securing justice in relation to the murders of Carol and Stephen.
“As with any investigation of this magnitude, everything we have uncovered is being reviewed and should anything suggest this has been the case we will not hesitate to act.”
Talks of a new house and dreams of travelling had been discussed, with both hoping to retire and spend their final decades in the company of loved ones.
Among those who were aware of their plans was Luke D’Wit, an IT worker who had been hired by Mr Baxter in 2012 or 2013 to help with the technical side of his shower mat business, Cazsplash.
The Baxters were unaware however that their trust in him would lead to their deaths, after he poisoned them with fentanyl and sadistically watched on camera as they deteriorated under the effects of the powerful opioid.
The dangerous killer was jailed for life in March, and is spending a minimum of 37 years behind bars for his despicable crimes.
The sentencing judge, Mr Justice Nicholas Lavender, said D’Wit “made some attempts to secure an indirect gain” for himself, but it was “distinctly possible that what really motivated you was a desire to control others”.
D’Wit’s trial was told that he created a gallery of fake personas to manipulate them in the two years before their deaths.
The defendant, of West Mersea, had pretended to be a doctor from Florida and members of a fake support group for the thyroid condition Hashimoto’s disease, which Mrs Baxter had been diagnosed with.
He later changed their will to make him a director of their shower mat company.
Detectives are reportedly reviewing the deaths of D’Wit’s father and grandfather in case the defendant killed them and avoided detection.
In his sentencing remarks, the judge said D’Wit “extracted… fentanyl from patches which had originally been prescribed for your father, who died in 2021, but which you retained in abundance”.
The 34-year-old had helped administer Mrs Baxter’s medication but had been secretly feeding her and her partner a cocktail of drugs that would lead to their deaths.
A toxicology report in June 2023 found that the powerful opioid painkiller fentanyl had been a factor, with an analysis of their stomach contents suggesting they had ingested the drug orally.
Just a day after their bodies were discovered, their will was rewritten on D’Wit’s phone, leaving him as the “director and person with significant control” of their business. It added that all decisions should be directed to him. A solicitor described it to jurors as a “very odd document”.
And disturbingly, it emerged that a “mobile security surveillance application” had also been downloaded on D’Wit’s phone, which allowed him to monitor a camera from the couple’s conservatory. During the final moments of their lives, he watched on his phone as the Baxters first became incapacitated by the drugs, then died.
When he was eventually arrested at his work for their murders, patches of fentanyl were found in his Adidas bag and his house was a “treasure trove of opened pills”, with a pestle and mortar also discovered.
While D’Wit claimed that the fentanyl found in his bag was to be taken to a pharmacy, pills with quadruple doses of promethazine were also found.
“There can only be one purpose for having these and that’s to fool someone into believing they were taking a proper dose when they were actually taking four times the amount,” prosecutor Tracy Ayling said.
The barrister said D’Wit “in the cruellest possible way was overdosing Carol Baxter on promethazine”, causing symptoms “like dementia, Parkinson’s and probably a stroke”.
Describing him as “one of the most dangerous men I’ve ever experienced”, Detective Superintendent Rob Kirby, of the Kent and Essex Serious Crime Directorate, said: “I have absolutely no doubt that had he not been caught, he would have gone on to commit further murders.”
DS Kirby said when he was sentenced that “justice has been served today”, adding that D’Wit “rightly belongs behind bars”.
He said: “He befriended people, came across as a very amenable, helpful person but in the background he was a cool, calculated killer who spent years planning the demise of Carol and Stephen Baxter.”
