Winston Landsman was nine years old when his mother died in a car crash. At least, that is what he believed until recently. In March, Landsman discovered cemetery records that state that his mother died in March 1974 from a "stab wound to the chest".“It was a hell of a surprise. As big as I am, I cried, ” he said.The records also identify Landsman's mother, Mona, with the surname of her boyfriend of the time.Now convinced that his mother was murdered, the private investigator from Saldanha Bay, Western Cape, has opened a case and asked the police to look into the 41-year-old mystery.Landsman, 50, found that hospital and court records on his mother's death no longer exist.Gauteng police spokesman Lieutenant-Colonel Lungelo Dlamini confirmed that the police docket could not be found but said the police would investigate if there were living witnesses.The entry in the death register states that Mona died of brain damage due to a "motor vehicle homicide". This confirms the story the family was told by Mona's boyfriend.Mona's sister, Mary-Anne Petersen, 59, remembers that when she saw Mona at Coronation Hospital, where she later died, there were no visible injuries attributable to the accident.The boyfriend identified Mona's body, paid for the funeral and handled all the paperwork relating to her death, Petersen said.No one knows why she was buried under his name. There is no record of their marrying.The Times could not reach Mona's boyfriend but his daughter said he had nothing to say.Landsman has applied to the Johannesburg Magistrate's Court for an exhumation order, hoping that an autopsy will establish the cause of death.Forensic pathologist Dr Candice Hansmeyer said pathologists may be able to tell quite a lot from 41-year-old remains if skeletal defects were present.But she was not convinced there is enough evidence to exhume Mona's remains and perform an autopsy.Hansmeyer said she was inclined to accept the cause of death provided on the death register.“The cemetery records [would have been] filled in by someone who isn't medically trained and would not have had access to a post-mortem report,” she said.But Landsman is undeterred. He needs to know the truth.As he awaits news on his exhumation application, he has also considered a costly private exhumation.At the very least, he wants his mother reburied under the family name.'There's always a blood trail'Criminals can be caught even if years have passed.“Somebody knows something, they just need to be found,” said private investigator Christian Botha.Botha found the body of Johannesburg businessman Alec Steenkamp, 43, who had been missing for eight years, within four days in 2004.Steenkamp disappeared in 1996 after he visited the home of Kenneth Downey on business.Botha said he found Steenkamp's remains, buried in Downey's backyard, after questioning Downey's neighbours.In 2005, Downey was sentenced to life in prison.Former tennis champion Bob Hewitt, 75, who was convicted in March of raping two of his teen tennis students and indecently assaulting a third, was brought to book 34 years after allegations were first levelled against him.There was no medical evidence relating to the attacks but the three women's combined testimony was enough to convince judge Bert Bam.Three men are currently on trial in the Johannesburg High Court, charged with the murder of chef Betty Ketani, who went missing in 1999.Thirteen years later, her remains were found after an alleged confession letter was discovered under the floorboards of a Johannesburg home. It was allegedly written by Carrington Laughton, who now stands accused with brothers Carel and David Ranger of Ketani's murder...