The serial murders of at least 156 women, men and children remain unsolved - and the families of one-third of them have no idea that their loved ones are dead.
While police say they have no accurate number of serial-killing victims who are never identified and are buried as paupers, an investigation by the Daily News has revealed that, in the past four years, this has been the fate of at least 51 people.
In KwaZulu-Natal detectives have been hard at work trying to track down the Fosaville serial killer, who killed 13 women between 1999 and 2003, and the Riverman killer, who raped and murdered 13 women between 1999 and 2001. The men operated in Newlands West and Greenwood Park and Newlands East respectively.
Only one of the victims in both cases was ever identified.
Inspector Desree Dudas, of the Organised Crime Unit, said there had been no critical developments in the case over the past two years. "There is a feeling that the Fosaville serial killer may be dead," she said.
"The docket is with me and it is still open, but we haven't identified any of his victims."
In May 2006, the faces of the Fosaville victims were identified using modern forensic technology. Despite the identikits being published in the Daily News, police have not been able to identify the victims.
In Gauteng, the trials of the "Moffat Park" and "Quarry Killer" alleged serial murderers continue, with police reporting that they are still battling to identify the bodies of 11 victims - who range in age from 16 to 60.
In the Moffat Park case, police have been able to identify only one of gardener Richman Makhwekwe's seven alleged rape and murder victims.
Serial killers - who almost always kill their victims by strangling and/or stabbing them - typically target disadvantaged black women as "perfect victims" for what psychology experts describe as premeditated, violent and emotional crimes.
According to Investigative Psychology Unit commander Dr Gerard Labuschagne, the modus operandi for local serial killers - about five of whom are arrested every year - is often chillingly similar.
"These people usually kill because they want power or for sexual reasons... there is almost always a sexual element to the crimes. They also tend to offer their victims employment to lure them away," he said, adding that the often desperate victims were all too eager to oblige.
Following the US and Russia, South Africa is rated third in the world for its known number of serial killers: 80 recorded since 1931.
Since 1994, 426 people - nearly all of them black women - are known to have been murdered by serial killers and, typically, dumped in the veld. Police claim they have a 70 percent success rate in catching the killers.
Authorities admit that identifying the victims is one of their greatest obstacles in catching suspects - particularly when all they can find are skeletal remains.
Typically the unclaimed bodies become just some of the 10 000 unidentified people buried nationally in R300 paupers' graves every year.
The 17 serial murder cases in which police have been unable to convict any suspects frequently involve unidentified victims. They include the following:
- In KwaZulu Natal: the murder of 13 women in Newlands East four years ago; the "Doringdraad" murders of 16 people in Empangeni in 1998; and the so-called "Riverman" murders, in which 13 women were raped, murdered and dumped in or near the Umhlangeni River.
- In Cape Town: the murders of 19 sex workers from 1992 to 1995; the "Station Strangler" killings of 22 children; the 1997 "Skiereiland Nagmerrie" murder of three people; the Stellenbosch child murders, in which three children were killed between 2001 and 2003; and the 1980s killings of six homeless people, who were shot within a 100m radius of Caledon Square police station.
- In the Eastern Cape: the teen sex-worker murders in Port Elizabeth in 2001, where five young women were raped, strangled and dumped. A businessman was charged with the murder of one of the women, but was acquitted because the State failed to prove its case beyond reasonable doubt.
"We do not need to identify a body in order to secure a conviction," Labuschagne said, but he admitted "it does make the task of investigation a great deal easier".
Labuschagne said suspected serial murder cases become more difficult to solve when the bodies of the suspected victims are badly decomposed and their cause of death could not be established.
"If there was blunt-force trauma or very deep stabbing, you will see that on the bones, but strangulation is difficult to establish unless a ligature has been used," he added.
Staff at Durban's Phoenix mortuary have told the Daily News that one or two skeletal remains were brought in every week.
"It's difficult to get those bones analysed because the State laboratory in Pretoria is so overburdened, and I think they would rather concentrate on helping a live rape victim than doing analysis on bones, especially if it (the possible murder investigation) probably won't go anywhere," one staff member said.
South African pathologists are, however, expected to testify in the ongoing trial of alleged Swazi serial killer David Simelane, who is accused of murdering 34 women and babies between 1999 and 2001.
The pathologists were called in to assist Swazi authorities to analyse the skeletons of Simelane's alleged victims, most of whom had been missing for more than a year. Simelane told a magistrate he killed the women because he had been falsely accused of rape by a woman and spent 19 years in jail. As a result, he had sworn to kill any woman he came across.
On Wednesday, the trial of the so-called "Jesus killer", 42-year-old Jimmy Maketta - who is facing 54 charges, including 16 counts of murder, 23 of rape, three of attempted murder and two of kidnapping - is expected to begin in the Cape High Court.