Kimberley - The investigator in the 2012 Griekwastad farm murders started his testimony in the Northern Cape High Court on Tuesday.
Colonel Dick de Waal, provincial commander of the organised crime unit, testified to arrangements he made after receiving a call about an alleged farm attack near Griekwastad.
The court was hearing evidence in the murder trial of a 16-year-old boy.
Griekwastad farmer Deon Steenkamp, 44, his wife Christel, 43, and daughter Marthella, 14, were killed on the farm Naauwhoek on April 6, 2012.
De Waal said he mobilised members of his own unit, the forensic unit, stock theft unit, and a police helicopter.
The investigator told the helicopter pilot to watch out for suspicious-looking vehicles on the main and gravel roads around Griekwastad.
De Waal asked the police from neighbouring towns such as Douglas to be on the lookout for possible suspects. He testified he met the youth at the restaurant across the road from the police station in Griekwastad.
De Waal said at that stage the boy did not cry, showed no emotion, and did not seemed very shocked.
He testified he saw a scratch mark on the boy's neck and some blood smears. Eventually he ordered that the boy be photographed and that samples of the smears and other evidence be gathered.
Earlier the court heard testimony from Marianna Smith and Elizabeth Vermeulen, Deon Steenkamp's sisters. - Sapa