How Original Sin weaves a mother's pain into the story of how Gerhard Jansen van Vuuren became a killer

In August 2022, Gerhard Jansen van Vuuren was handed a life sentence in the Gauteng High Court for murdering his ex-girlfriend, Andrea Venter, in 2011.

He'd stabbed her 14 times, before slitting her throat.

The verdict followed years on the run - van Vuuren fled South Africa when he was first out on bail for Brazil, where he started families with multiple women before being extradited in 2020.

A documentary telling his story, mainly through the voice of his mother, has just premiered on Showmax.

It's called Original Sin: My Son The Killer.

After helping her son escape, Thea Pretorius slowly came to terms with him being a murderer.

In conversation with producers Jana Marx and Sarah Laita, Sara-Jayne Makwala King remarks that it is almost more difficult to witness the story behind the killer than knowing the film will result in a murder.

In terms specifically of the family's history of gender-based violence, it is not only a South African story but one that transcends borders, says Laita.

"All gender-based violence cases are horrific in their own ways and, sadly, sometimes it can lead to a murder. I think understanding the psychology of this and why it is someone came to do something like this, is really important."

"I'm very proud of the way we managed to explore that in this film."

Sarah Laita, Producer - Original Sin

From a documentary perspective, you listen to as many voices as possible says Marx, and a story sometimes just tells itself.

"Thea is leading us through the story. It just made sense to obviously interview her as the mother... and then realising she has so much to contribute to this theme, there is so much deeper here...:

"This is not about a film whodunnit, this documentary is about understanding why these things happen."

Jana Marx, Editorial Producer - Original Sin

The big question is how far a mother would go to protect her child, Laita adds.

As she puts it, it's unfathomable really how to deal with knowing your son has done something wrong and needs to face justice.

"I think Thea's character is so complex in so many ways... All of us from the production side thought she was really brave for telling this story and for being so honest with her journey."

Sarah Laita, Producer - Original Sin