BRAKPAN - The family of slain Witness D says they'll only find closure when all his killers are arrested.
Marius van der Merwe was gunned down in December outside his Brakpan home.
The former EMPD officer and security company owner had just testified about corruption and an alleged police cover-up at the Madlanga Commission.
READ: Van der Merwe's alleged murderer a highly trained former police officer
A specialised task team arrested 41-year-old Matipandile Sotheni in Johannesburg over the weekend.
Sotheni appeared in the Brakpan magistrate's court on Monday where his case was postponed to 25 March.
READ | Suspect linked to Witness D murder to appear in court
Sotheni faces several charges, including murder, conspiracy to commit murder, attempted murder and being in possession of an unlicensed firearm.
Van der Merwe’s sister, Natasha Van der Merwe, said the killing has had a profound impact on her life.
She has been diagnosed with post-traumatic stress disorder (PTSD) and severe trauma.