“No one could have predicted the crimes,” forensic psychiatrist Larissa Panieri-Peter said during questioning by Riaan Bode, for the boy.
She was testifying during sentencing proceedings of the 17-year-old boy convicted of killing the Steenkamp family on their farm.
The court found the boy guilty on March 27 of killing Griekwastad farmer Deon Steenkamp, 44, his wife Christel, 43, and their daughter Marthella, 14.
They were shot dead on their farm Naauwhoek on April 6, 2012.
The boy was also found guilty of raping the girl and lying to police.
Panieri-Peter said such a crime was rare.
“(There is a) lack of literature on cases such as this.”
Replying to Bode’s questions about long-term imprisonment, she said: “What happens to people in prison is harmful.”
Although the court could not be restrained by this fact, a balance had to be struck between the minor’s further mental development and imprisonment, she said.
“Going to prison is seldom good for any person. But looking at things such as access to good social workers is helpful.”
She said the boy needed a great deal of psychological help.
During cross-examination by prosecutor Hannes Cloete, Panieri-Peter told the court she could find no evidence that the boy had derived pleasure from the murders.
There was not even evidence that he had ever been cruel to animals.
Cloete asked Panieri-Peter to comment on how the murders were committed.
“It was a hideous crime. That is why I said the nature of the crime is significant. (It) speaks to intense emotions.”
The matter continues.