But in the drama unfolding in the Durban Supreme Court, where the former South African defence minister, General Magnus Malan, and 19 co-defendants, face charges for 13 gruesome apartheid murders, Mr Opperman is the closest thing to a celebrity this case is likely to produce. The 38-year-old former soldier is unquestionably the star witness for the prosecution in the new South Africa's first trial of apartheid-era crimes.
In four days on the witness stand last week - most of the time under defence cross-examination - Mr Opperman has riveted South Africa with tales of training a Zulu force to fight Nelson Mandela's African National Congress (ANC); a botched hit squad attack; animal sacrifices and his own confession that he was a murderer who, under the right circumstances, would kill a five-year-old child without flinching.
Mr Opperman was the white commander of a 10-man Zulu paramilitary unit which, in the small hours of 21 January 1987, gunned down 13 people, mainly women and children, in a bungled assassination attempt. The intended target, Victor Ntuli, a local anti-apartheid activist, was not at home at the time of the raid. The unit instead hit a prayer meeting with automatic gunfire and military precision. The results of the operation are now known as the KwaMakhutha massacre.
Mr Opperman is seeking indemnity in return for his evidence against Gen Malan and the 19 others charged with murder, attempted murder or conspiracy to murder. With so much riding on the trial, it was a deal that the prosecutor, Tim McNally, was keen to make. Mr Opperman was kept in hiding abroad until his first appearance in court on Tuesday, and police said today that they are taking seriously a threat to kill him.
Gen Malan and his co-accused sat motionless in the dock while two women survivors testified how they had hid as other people in the house were killed. But the poker faces slipped when Mr Opperman arrived. He started with his 1986 recruitment into what became known as Operation Marion (short for marionette), which was an apartheid-regime plan to use a puppet force from the Zulu Inkatha movement - the main rival to the ANC - to provoke violence among blacks.
He described the path which led from the training of 206 Inkatha soldiers to the eventual massacre. He said he received his orders from all of the former white minority government's military brass sitting before him in the dock, with the exception of Gen Malan.
On Thursday, he said the massacre was a "fiasco" resulting from a bad intelligence report. Even though the attack failed to hit its intended target, it was viewed as a success in the sense that it was not linked to the military. But his men were so horrified when they learned they had killed innocents that they sacrificed a goat to remove the bad spirits.
Under cross-examination Mr Opperman admitted to being a murderer, but denied being a mass murderer.
Gen Malan and all his co- defendants have pleaded not guilty to the charges against them. The trial continues.