The Oscar Pistorius trial is under way, and in yesterday's testimony, his ex-girlfriend took the stand to testify that not only did the "Blade Runner" cheat on her continuously, but he kept a gun by his bed... perhaps to offer testimony that Oscar was of less than favorable moral fiber?

CNN is reporting that Samantha Taylor, who was 17 when she met -- and subsequently began dating -- Oscar, testified that he cheated on her with the murder victim, Reeva Steenkamp, causing the demise of their relationship. In addition, she testified that he kept a gun by his besides (next to his prosthetic legs, if it's a visual you're craving), and his temper was so volatile that he once shot a hole through their car roof during one of his tantrums.

However, Pistorius' attorney, Barry Roux, brought Samatha's testimony into question with a few follow up questions: she couldn't remember where, or on what day, the alleged "shooting a hole in the car roof" situation happened; she admitted to cheating on Pistorius when they broke up the first time; and she later admitted that Oscar said he was "joking" after one of his tantrums, and was laughing after he shot a hole in the roof of the car.

Meanwhile, according to The New York Daily News, Oscar's neighbor Johann Stipp also testified at the trial. In his testimony, Stipp claimed that Oscar was "praying to God" that Reeva Steenkamp would live after the shooting -- even though the fact that it was a head wound would have made that prayer a nearly-impossible one to fulfill. "Please let her live, she must not die," Pistorius cried out, Stipp said. "He said while he was praying he would dedicate his life to God and her life to God if she only lived."

But Stipp, who is a physician, said he tried to open an airway for the model and actress, but quickly realized she was beyond salvation. Stipp testified that Steenkamp had no peripheral pulse, and no signs of life.