From elite cop to murder accused: The man behind the killing of Witness D

A case that reads like a crime thriller

It’s the kind of story that feels almost too cinematic to be real, a highly trained former police officer, a whistleblower gunned down outside his home, and a web of connections that stretches deep into law enforcement itself.

But this is not fiction. It’s unfolding in Gauteng, and it’s raising uncomfortable questions about trust, power, and the very institutions meant to protect the public.

At the centre of it all is Matipandile Sotheni, a 41-year-old former member of South Africa’s elite police unit, now accused of assassinating a key witness.

The killing that shocked Brakpan

The victim, Marius van der Merwe, was shot and killed in a drive-by attack outside his home in Brakpan on 5 December 2025.

Van der Merwe wasn’t just any victim. A former EMPD officer and security specialist, he had recently testified before the Madlanga Commission, exposing alleged wrongdoing within the Ekurhuleni Metropolitan Police Department.

In other words, he was a whistleblower and now, investigators believe he may have been silenced.

A suspect with elite training

What makes this case particularly chilling is who police say pulled the trigger.

According to Athlenda Mathe, Sotheni wasn’t just another criminal. He joined the South African Police Service in 2005 and later became part of the highly specialised Special Task Force in 2010 one of the most elite and rigorously trained units in the country.

Members of this unit are trained for high-risk operations, including hostage rescues and tactical interventions. That level of training, Mathe suggested, could explain the precision of the killing.

It also adds a disturbing layer to the case: the same skills meant to protect lives may have been used to take one.

The alleged accomplice and a trail of violence

The investigation doesn’t stop with Sotheni.

Police have linked the case to Wiandre Pretorius, a police informant who allegedly drove the getaway vehicle, a Suzuki Swift later traced back to Sotheni’s girlfriend.

Pretorius, however, will not stand trial. He died by suicide at a petrol station in Brakpan.

His name has surfaced before in connection with violent crime. He had previously survived a shooting in which his car was hit multiple times, and he has also been linked to the unresolved murder of another individual, whose body was found in Nigel in 2022.

For investigators, these connections paint a broader, more complex picture of criminal networks and overlapping roles.

Inside the courtroom

When Sotheni appeared in the Brakpan Magistrate’s Court, the atmosphere reflected the seriousness of the case.

He stood alone in the dock, dressed in black, as heavily armed officers guarded both the inside and outside of the courtroom a visible reminder of the stakes involved.

According to Lumka Mahanjana, he faces multiple charges, including premeditated murder, conspiracy to commit murder, attempted murder, and unlawful possession of ammunition.

The State is expected to oppose bail when he returns to court on 25 March.

A blow to public trust

For many South Africans, this case hits close to home, not just because of the violence, but because of who is accused of carrying it out.

The idea that a former member of an elite police unit could be involved in such a crime is deeply unsettling. Training a Special Task Force member costs more than R1 million, according to police, a significant investment now overshadowed by allegations of criminal activity.

But officials have also framed the arrest as a sign that the system is working, that even those within the ranks are not above the law.

Social media reaction: shock and suspicion

Online, the reaction has been swift and intense.

Many South Africans have expressed shock that someone with such a high level of training could allegedly turn to crime. Others, however, say the case confirms long-standing fears about corruption and infiltration within law enforcement structures.

There’s also a strong sense of concern about whistleblower safety, with some questioning whether enough is being done to protect those who come forward.

A bigger story unfolding

At its core, this case is about more than one man or one crime.

It’s about the risks faced by those who speak out, the vulnerabilities within powerful institutions, and the fine line between order and lawlessness.

As the investigation continues, South Africans will be watching closely, not just for justice in this case, but for what it reveals about the systems meant to uphold it.