Sean Rens, manager of the International Firearm Training Academy in Walkerville town, also said he had many conversations about firearms with Pistorius, who is accused of murdering his girlfriend, Reeva Steenkamp. He said the double-amputee runner had "a great love and enthusiasm" for guns.
Rens said he met Pistorius in 2012 and trained in a gun range with him, and that Pistorius was seeking to collect guns. In one conversation, Pistorius described how he was startled by a noise at home and decided to clear the house by drawing his gun and checking rooms, according to Rens.
"He went into what we call 'code red' or combat mode," Rens said. "When he came to the source of the noise, it was the laundry or something."
Pistorius had tweeted about the incident in November 2012: "Nothing like getting home to hear the washing machine on and thinking its (sic) an intruder to go into full combat recon mode into the pantry!"
Pistorius said he killed Steenkamp by accident before dawn on Feb. 14, 2013, shooting her through a closed toilet door after mistaking her for an intruder in his home. Prosecutors say he killed her intentionally after an argument.
Prosecutor Gerrie Nel asked Rens to describe how Pistorius was quizzed on how to handle a firearm in various scenarios, for example when two unidentified men approach the house of a gun owner; then when they break into the house, begin to steal belongings and order the gun owner to leave; and if the men threaten to kill the gun owner, who is behind a security gate in the house.
In each case, Rens said, Pistorius correctly answered "No" when asked if it was OK to fire at the men. He correctly said he was only entitled to shoot at them if they advanced on him with a gun, according to Rens.
Nel was trying to show that Pistorius flouted those regulations when he shot Steenkamp. Pistorius says he fired because he thought he was under threat.
Rens said he was introduced to Pistorius in May 2012, a few months before the runner made history by competing at the London Olympics. Pistorius wanted Rens to find a "specific" gun for him, Rens testified, a Smith & Wesson 500 revolver handgun.
Rens also listed five other guns Pistorius was hoping to procure under a collector's license. They were a .38-caliber Smith & Wesson revolver, the civilian version of a Vector .223-caliber assault rifle, and three shotguns: A Mossberg shotgun, a Maverick shotgun and a Winchester shotgun.
Pistorius applied to the South African police's National Firearms Centre for licenses to own these guns on Jan. 22, 2013, according to the center's records, just three weeks before he shot dead Steenkamp in his home using his 9 mm Parabellum pistol, the only gun he was licensed to have at the time, for self-defense.
Pistorius' applications for licenses for the other six guns were not processed and were instead "sent back" four days after he killed Steenkamp, officials at the South African police's National Firearms Center told The Associated Press last year.
In later testimony Monday, police photographer Bennie van Staden spoke about the images he took when he arrived at Pistorius' house on the night of the killing. One photograph of the runner, taken in his garage, showed unexplained scuff marks on his bloodied prosthetic limbs.
Another photograph from the Paralympian's bedroom showed a box with a label that said "Testis compositum."
The runner's representatives have identified the substance as an herbal remedy used for "muscle recovery." A product by that name also is sold as a sexual enhancer. Testis compositum is marketed by some online retailers in both oral and injectable forms as a testosterone booster and sexual performance aid that contains the testicles, heart and embryo of pigs, among other ingredients. Some retailers also say it can be used to treat fatigue.
Also found in the bedroom was a box with the label "Coenzyme compositum" as well as syringes and needles.
Steenkamp's mother, June, was in the Pretoria courtroom for a second time Monday but had left by the time van Staden was describing the photos being displayed of the bloody bathroom scene where her daughter was shot.
June Steenkamp last attended the trial on the opening day on March 3.
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