Friends support the Griquatown teenager at the Northern Cape High Court. File photo: Danie van der Lith

Kimberley - The defence team for the Griquatown farm murderer has called a forensic and juvenile criminologist to testify in mitigation of sentence for the teenager on Tuesday.

The 17-year-old's defence counsel Riaan Bode told Judge Frans Kgomo that they would continue to present evidence during the teen's sentencing procedures this week.

Bode called Dr Eon Sonnekus, a juvenile criminologist, to the stand to testify.

Kgomo postponed the matter to Tuesday after the previous session in which the defence also presented the court with various evidence for mitigation in the court's sentence.

The teenager was earlier found guilty for the murders of 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.

He was also found guilty on a charge of raping the girl and lying to the police. - Sapa