The case set a precedent in South Africa in terms of juveniles and capital punishment; while the Criminal Procedure Act, 1977 permitted the sentencing to death of a person under 18 years, S v. Lehnberg made clear that an abundant presumption, given the presupposition of immaturity, would be in favour of a prison sentence for minors convicted of capital crimes.
In February 1972, Lehnberg began her first job as a clerical assistant/receptionist at the Red Cross Children's Hospital in Rondebosch, Cape Town.
Van der Linde was the workshop's chief technician and Lehnberg, a bright, intelligent and attractive 16-year-old, was apparently drawn to him from the start.
She had not been allowed to socialise and had never been to the cinema during the time she was in high school, she was a very intelligent young girl academically and often came first in her class but had no experience of boys or men, she was very naive and innocent and tried hard to get attention via her studies.
Van der Linde and Lehnberg struck up a father-daughter type relationship which grew closer as the months passed.
Throughout the remainder of 1973, Lehnberg and Van der Linde continued to meet in secret at Rondebosch Common and Paarden Eiland.
Christiaan van der Linde persuaded her not to, but by September she had finally tired of the situation and decided to confront Susanna.
Initially, Lehnberg had hoped that she and Susanna van der Linde could come to some sort of arrangement concerning Christiaan, but this meeting was to change all of those ideas.
It was around this time that Lehnberg met Marthinus Charles Choegoe, who had lost a leg in a motorcar accident.
Lehnberg first contacted Choegoe by letter, which she wrote to him care of Solly's Trading Store, his local shop.
Several days later he went to the address in Boston, Bellville which Lehnberg had given him, later claiming that he planned to warn Susanna van der Linde that her life was in danger.
Lehnberg gave him a radio and promised that she would help him to receive an artificial limb if he did away with Susanna van der Linde.
In October 1974 Lehnberg handed in her notice at the hospital and told van der Linde that she was going to leave Cape Town.
A few days after Choegoe's failed attempt, she approached Rob Newman, a 24-year old engineering student whom she knew, and asked to borrow his Llama pistol.
On the morning in question, Marais had walked past Lehnberg's white Ford Anglia twice in the space of ten or twelve minutes while it was parked opposite the van der Linde house and on both occasions the car was empty.
It was suggested at the time that van der Linde had influenced Lehnberg in order to get her to murder his wife but this was not proven and he was never charged.
van der Linde attempted to telephone his wife a number of times that morning and eventually became concerned when there was no reply.
He spoke to his daughter Zelda, who worked at Tygerberg Hospital, and asked her to go home during her lunch break to see if there was anything wrong.
When she arrived home the house was locked up, but through a window she caught a glimpse of her mother lying on the floor in the living room.
In fact, it was because of Choegoe that Susanna van der Linde insisted that her husband buy her a dye pistol.
She added that she had been expecting the police to contact her ever since she first heard about the murder of Susanna van der Linde from her mother.
Fourie also asked her if she had once requested a Robert Newman to give her his pistol so that she could get rid of Susanna van der Linde.
Although Fourie had no specific evidence to tie Lehnberg to the murder it did strike him that she seemed unnaturally nervous at times during the interview.
While Fourie was on the telephone to Cape Town another detective, Major van Aswegen, began asking Lehnberg questions.
Later that day she made a full statement in which she admitted that she had asked Choegoe, if he would do away with Susanna van der Linde.
After the trial, he moved to Krugersdorp so that he could visit his wife's grave on her family's farm in the Magaliesberg mountains every day.