"He said to Oscar that the gun could not just be left on the seat there," Taylor said, adding that bullets fell out of the gun "and then Oscar got very angry and eventually they gathered the bullets."
An angry Pistorius shouted at the officer and later, after leaving the scene, he fired the gun out of the sunroof, she said. He and Fresco were laughing at the time, according to Taylor. Roux said Pistorius had denied the incident.
Pistorius says he killed Steenkamp in his home in the early hours of Valentine's Day 2013 by mistake, thinking she was an intruder. Prosecutors say he intentionally killed her after an argument.
After prosecutor Gerrie Nel asked permission from the judge to uncover possible new evidence at the end of the former girlfriend's testimony, Taylor described previous incidents when Pistorius thought there was an intruder trying to get into his home, and he reacted by waking her up, she said.
"There was one occasion when something hit the bathroom window and Oscar woke me up and asked me if I heard it," Taylor said. "He got up with his gun."
But he woke you up, Nel asked.
"Yes. There was probably one or two occasions when he woke me up to ask me if I heard something," Taylor replied.
Pistorius did not attempt to wake or locate Steenkamp before he shot the 29-year-old model by mistake, according to his own version of events.
Taylor said Pistorius always kept his gun on a table by the bed at home, and always slept on the right side of the bed. Pistorius says his 9 mm pistol was under the bed on the night he shot Steenkamp and he says he was sleeping on the other side of the bed because of a sports injury.
Roux has contended that other witnesses who testified to hearing a woman's screams on the night of the killing were mistaken, and that they were actually hearing the high-pitched woman-like screams of Pistorius, mainly after realizing he had shot Steenkamp. The athlete has pleaded not guilty to murder and several firearms charges.
Taylor, however, said she had heard Pistorius shouting at her and other people and that he did not sound like a woman.
"He sounds like a man," she said.
