During cross examination in High Court in Pretoria, Sean Ren read from a competency test Pistorius took in which the athlete answered that a person should only use a gun if his or her life is knowingly being threatened and that a person must be sure of his intended target and what lies beyond, the South African Broadcasting Corp. reported.
Ren, manager of the International Firearm Training Academy, also said Pistorius answered "no" to questions about whether it was OK to shoot an intruder who enters a residence to steal stereo equipment, the SABC said.
Pistorius, a Paralympian and 2012 Olympics competitor dubbed "Blade Runner" because of the shape of the prostheses he uses on his lower legs in order to run, is charged with shooting Reeva Steenkamp to death through a bathroom door. He has said he thought he was shooting an intruder.
Sen said he sold Pistorius several guns in 2012 and that the athlete canceled the purchase of several weapons, including a pistol, shortly after Steenkamp was slain in February 2013.
Testimony concluded for the day after police photographer Bennie van Staden described in detail the numerous graphic photographs he took at the shooting scene.
Van Staden also testified Pistorius was quiet while at shooting scene and cried. He said the athlete told police he had washed blood off his hands.
The SABC said Pistorius greeted Steenkamp's mother, June, who attended the trial for the first time since the day it began. The Daily Telegraph reported the victim's mother left the courtroom before the conclusion of the day's testimony.