Johannesburg - Carlos Higuera, who is accused fatally stabbing of Chumani Nqakula, the son of Defence Minister Nosiviwe Mapisa-Nqakula, is not fit to stand trial, the Johannesburg Magistrate's Court heard on Tuesday.
Prosecutors told Magistrate Albertus Roux that three psychiatrists had concluded that Higuera suffered from a mental illness.
The matter would now be handed over to the director of the NPA in South Gauteng to make a final decision.
The prosecution said the Nqakula family would also be consulted.
Higuera would remain at the Sterkfontein Psychiatric Hospital.
Nqakula was stabbed in the upper body in October 2015 in Bezuidenhout Valley, while his mother was abroad for work.
Chumani's father, Charles Nqakula, was previously the minister of defence and later the minister of safety and security. He is currently high commissioner to Mozambique.