What does it mean to fire a gun “accidentally”? If you point a gun at the door to a tiny cubicle, believing, you say, that a person is behind it, and fire four shots, can you also say, “I didn’t shoot at anyone. I didn’t intend to shoot at someone.… I didn’t shoot or intend to kill anyone”? That is the testimony of Oscar Pistorius, who is on trial for murdering his girlfriend, Reeva Steenkamp. In a remarkable few days of cross-examination, Pistorius, an Olympian and a Paralympic sprinter, has, according to press accounts, placed the blame for his legal predicament on the police, his friends, his father, an ex-girlfriend, his own lawyers, and Steenkamp herself, who was behind the door when he shot. His defense is that he thought she was a burglar. Addressing the judge, he said, “My lady, I wish she had let me know she was there.”

But, then, guns behave strangely in Pistorius’s hands. As he tells it, they have an eerie autonomy. “I didn’t have time to think,” he has said, over and over again—only to pull the trigger, and pull it three more times again—as if the absence of thought attached to that act, the power of the gun, was an absolution. And sometimes, the trigger even pulls itself. Pistorius is being tried for Steenkamp’s murder, and for two other incidents in which he allegedly fired a gun. One was in a restaurant, when he asked to see a friend’s gun and took it from him under the table. While it was in his hands, and no one else’s, a bullet was fired. On the stand, he said that his friend was “stupid” to give him a loaded gun—and that, anyway, he, Oscar Pistorius, didn’t fire it. “I physically didn’t discharge it. It went off when it was in my possession, but I did not have my finger on the trigger,” he said.

“The gun went off by itself?” Gerrie Nel, the prosecutor, asked.

“I know that my finger was not on the trigger,” Pistorius said.

As it happens, this particular gun, a Glock, has a safety feature that keeps it from discharging unless the person who is holding it has his finger fully on a sort of trigger-within-the-trigger and pulls. For the gun to have gone off otherwise would have been a “miracle shot,” as the prosecutor put it. This point is one of several, during three days of testimony so far, in which one wonders why Pistorius doesn’t take at least a degree of responsibility—saying, for example, that he pulled the trigger thinking the gun was empty, to get a feel for it. Instead, he has come across as a man so fixated on justifying himself that he can’t even hear it when he sounds illogical or cruel. After the shooting in the restaurant, he asked his friend to lie about what happened and take the blame.

In addition to the miracle shot, there was the phantom bullet. Two people, Pistorius’s friend Darren Fresco and his ex-girlfriend Samantha Taylor, testified that they were in a car with Pistorius when he was stopped for speeding. The policeman saw his pistol on the seat, picked it up, and admonished him before giving it back. Fresco and Taylor both said, under oath, that after they drove off Pistorius, in a state of rage at the officer, fired a shot through the roof. Pistorius, on the stand, called them both liars, saying that they had “fabricated” the shooting. But he did go on about how he was offended by the policeman’s behavior—even though this is what policemen are meant to do in such situations. As Andrew Harding, of the BBC, said, “Mr. Pistorius’s criticism of the policeman’s lack of ‘courtesy’ and ‘professionalism’ spoke volumes about his attitude to authority in South Africa—a country where some cocky white men still do not always show appropriate deference to the country’s racial sensitivities and legacies of apartheid.” (Harding called the cross-examination, which resumes on Monday, “close to a disaster for Mr Pistorius—and one that largely seems to have been of his own making.”

Pistorius said that Samantha Taylor, who was nineteen when they were dating, had perjured herself on another point, too: she testified about times when he “screamed angrily” at her. “I never screamed at Miss Taylor,” Pistorius said. But he has said that Steenkamp had it all wrong, too. In a series of lengthy texts, she indicated that he had thrown “tantrums” and had “snapped at” and “picked on me,” and made a scene when he wanted to leave a party earlier then she did, after falsely accusing her of flirting. He said he never picked on her, “never lost my temper or shouted at her”; he had simply tried to correct her behavior—explaining that chewing gum “looked bad on camera” and that she was talking in a voice that “annoyed me.” He had no idea she wanted to stay at the party—and, really, it did look to him like she was flirting. She should have known better.

“So Reeva lied?” Nel asked.

Steenkamp, Pistorius said, “exaggerated.”

Pistorius’s story is that, before he fell asleep, he told Steenkamp, who had cooked him dinner earlier and was in bed with him, looking at her phone, to bring some fans in from the balcony. He woke up at about three and saw that she hadn’t—another failing—and got up to bring them in. (Photos of the scene showed the fans and other objects in places they couldn’t be if his narrative was right; he said that he police must have moved them all around.) Then he heard a window opening in the bathroom, which he decided was an intruder; he got his gun from under the bed without noticing, he said, that Steenkamp was no longer in it—“You never checked if she was scared. Your first thought was to arm yourself,” the prosecutor said—headed to the bathroom, passing by a bedroom door, through which he might have directed her to a safer part of the house; and pointed his gun at that little cubicle. He says that he shouted to Steenkamp to call the police; he hasn’t explained why, if he did, there was no reply, or he didn’t wait for one. (Under South African law, he could also be convicted of culpable homicide, or manslaughter, for shooting an unknown person behind the door.)

On Friday, Nel and Pistorius had an exchange about the possibility that Steenkamp screamed, perhaps as she was dying in that tiny cubicle, that is telling in its absurdity. “She’s awake. She’s in the toilet. You’re shouting. You’re screaming. You’re three metres from her. She would have responded. She would not have been quiet, Mr. Pistorius,” Nel said. Pistorius replied that she never, ever cried out; then he said that, with the ringing in his ears from the gun going off again and again—“the decibels”—he couldn’t have heard anything.

NEL: How can you exclude the fact she was screaming if you couldn’t hear?”

PISTORIUS: If I couldn’t hear it, then I couldn’t hear.

NEL: No, you said, Mr. Pistorius, “she never screamed.” You couldn’t hear. You’re just saying that.

Pistorius persisted: “A woman did not scream at any point,” he said. If didn’t happen from his perspective, it just didn't happen.

The screams matter because other witnesses have said they did hear a woman crying out, before the shots were fired. Some thought it sounded like an argument. Pistorius has called them liars, too.

“She wasn’t scared of an intruder. She was scared of you. She was scared of you,” Nel told Pistorius. “She was standing right in front of the toilet door, talking to you, when you shot her. That’s the only reasonable explanation why you shot her in the head.” Pistorius denied it. This is, for him, where it becomes a story about what his gun did.

Photograph: Themba Hadebe/AP