Evil woman who helped murder and dismember Sarah Mayhew was ’empowered by brutality’

WARNING: DISTRESSING CONTENT. Criminologist Alex Iszatt believes Gemma Watts was always capable of the sadistic murder, but was ‘waiting for the right person to bring it out’ of her

A woman who helped a convicted killer murder Sarah Mayhew before dismembering her body and dumping parts around south London had “darkness inside her all along” and was just “waiting for the right person to bring it out,” a leading criminologist believes.

Steve Samson was out of prison on a life licence for the murder of a taxi driver in 1998 when he and his partner, Gemma Watts, killed 38-year-old Sarah, at his flat in Sutton last spring.

The murder “involved sexual and sadistic content”, according to the judge at the Old Bailey, who today sentenced Samson, 45, to life imprisonment with a whole-life order, meaning he will never be released from prison. Watts, 49, was sentenced to life imprisonment with a minimum term of 30 years, and will spend the rest of her life on licence if she is ever released.

Watts, who had met Samson on a dating website, laughed and giggled in court, winking at her co-accused Steven Sansom, whom she called her “evil twin”.

The pair admitted Sarah between March 7 and April 3, after inviting her to come over for a party, before slitting her throat and later chopping up her body.

The bloodthirsty killing caused shock and revulsion, with many wondering how Samson managed to convince Watts, who had no criminal record, to be a willing accomplice in his crime.

But Alex Iszatt, a former crime scene investigator, believes Gemma Watts was just as evil and dangerous as Samson – but just hadn’t yet found someone who shared her depravity. And when both got together and shared their extreme fantasies, any obstacle to carrying them out was removed.

She says: “When two people with these urges find each other, they don’t just share them; they escalate them. Alone, one might hesitate. Together, they remove each other’s last shred of doubt.”

The Old Bailey heard how Samson and Watts began a depraved seven-month relationship where they exchanged messages about shoving his hand down her throat and making her vomit, watching pornography involving dogs, and a video of Sansom beating Watts with a wooden spoon.

Messages between the pair included a letter in which Watts said Sansom should have no liability if she died during one of their sex games. There were also messages about them having sex covered in blood and the two dying together if they were ever caught.

The court also heard a voice note in which Sansom said, “Everyone looks like meat now, don’t they? It’s a play thing. Something to cut, something to bleed.” Watts responded, “I wonder what they taste like, cooked flesh.” Sansom replied, “People taste like pork; consistency and texture are the same.”

Alex says: “Unlike Sansom, [Watts] had no history of violence, yet she didn’t just assist – she took an active role in dismembering Sarah Mayhew. Was she manipulated, or did she have this darkness in her all along, waiting for the right person to bring it out?

“Watts’ actions suggest far more than fear or coercion—she seemed to revel in the depravity. In court, she giggled and winked at Sansom, calling him her ‘evil twin.’ Her role in the murder wasn’t passive.

“The chilling voice messages exchanged between them, where they discussed graphic violence and cannibalistic urges, show how Watts wasn’t just an unwilling accomplice -she actively embraced and pushed these acts further. She didn’t just follow Sansom; she found empowerment in their shared brutality.

Sansom’s influence was undeniable—he had already killed before, making it easier for him to rationalise the unthinkable. But Watts wasn’t a passive observer. She didn’t just accept his depravity; she thrived in it. That makes her just as dangerous, if not more so.”

The pair also exchanged depraved voice notes about cannibalism. Alex says: “Most people would be disgusted at the mention of cannibalism. .Most killers, even the most brutal, never go there. It’s the ultimate taboo, an act of complete domination that erases not just a life but the very idea of personhood.

“That Sansom and Watts even discussed it shows how far they had already detached from reality. If murder wasn’t enough, what was their next step? The fact that Sansom had killed before raises another disturbing question – had he already crossed that line in the past?”

She adds: When two people like this come together, their combined depravity becomes a force of its own. They push each other to go further, spiralling into acts even they may not have imagined at the start.”