Alleged "Modimolle Monster" Johan Kotze will undergo further psychological tests in Bloemfontein before his trial resumes next year, the High Court in Pretoria heard on Friday.
The trial was postponed on Friday to 4 February next year, because the last two state witnesses were not available.
A doctor specialising in sexual violence cases still has to complete her evidence.
The State will also call to the stand the specialist who treated Kotze's estranged wife Ina Bonette after the attack.
Judge Bert Bam ordered that Kotze be transferred to the Grootvlei prison near Bloemfontein for further psychological and psychiatric assessment.
He made it clear that Kotze's transfer would be dependent on the availability of accommodation at the prison.
Kotze's advocate Bernard Bantjes earlier told the court that Kotze questioned the report by three psychologists at the Weskoppies psychiatric hospital who found him fit to stand trial.
He said the issue of Kotze's accountability would be placed in dispute on both a pathological and non-pathological basis.
When asked repeatedly to state his client's defence and to state if this included that he could not follow court proceedings, Bantjes said he had instructions that Kotze understood the proceedings.
Bam, at the commencement of the trial, refused a postponement so that Kotze could be assessed for a second time and ordered that the trial proceed.
Kotze, Andries Sithole, Pieta Mohlane, and Frans Mphaka are accused of murdering Kotze's 19-year-old stepson Conrad Bonette at Kotze's house in Modimolle on 3 January this year.
They are also accused of kidnapping, severely assaulting, repeatedly raping, and attempting to murder Kotze's former wife earlier that day.
A plea of not guilty was noted on behalf of Kotze after he refused to enter a plea, claiming his accountability and ability to follow and contribute to court proceeds was in question.
His three co-accused all pleaded not guilty to the charges.
They claimed Kotze had forced them to take part in the attack on Bonette and claimed they had only pretended to rape her, because they could not get erections.
All four accused will remain in custody.
Bonnette testified how Kotze had tortured her with various objects and cut or sawed off both of her nipples before he instructed the other three to rape her.
She was made to listen to her son pleading for his life before Kotze allegedly shot him in the head and heart.