PRETORIA, South Africa – More than halfway through the defense's evidence in the trial of Oscar Pistorius, their strategy appears to be simple: build ambiguity about everything.
In presenting their case against the Paralympian, the state prosecution used the analysis of police forensic experts to paint a picture of a Valentine's morning filled with arguments and anger, where Pistorius shot and killed his girlfriend in a fit of rage.
They say model Reeva Steenkamp was awake and eating two hours prior to her death, and that she was cowering, terrified, in a locked toilet cubicle, when she was shot through the door.
But instead of attempting to fully disprove the state's experts, the star athlete's defense has begun to call a host of its own experts to ensure it is clear to the court – and Judge Thokozile Masipa – that nothing is for certain.
Disputing the accuracy of the prosecution's ballistics analysis and reiterating the questionable science around gastric emptying, defense attorney Barry Roux appears to be focused on building reasonable doubt.
Thursday, as the trial entered its 28th day, specialist anesthetist Christine Lundgren testified – in agreement with state pathologist Gert Saayman and defense pathologist Johan Botha – that gastric emptying is an "inexact science."
Saayman's report details the vegetable and "white cheesy matter" found in Steenkamp's stomach after her death, and on the stand earlier in the trial the state expert – forced to reluctantly estimate the time of her last meal – suggested she had eaten around 1 a.m., more than five hours after her Valentine's Eve dinner with Pistorius.
Prosecutor Gerrie Nel claimed this as proof of the athlete's dishonesty, although Pistorius protested that his girlfriend could well have had a late-night snack while he was asleep.
Lundgren told the court Thursday that various factors could have delayed gastric emptying, including several relevant to Steenkamp's situation: sleep, her yoga exercises before bed and being a pre-menopausal woman.
Questioned about Saayman's ability to discern vegetable matter in the model's stomach – Nel suggested it showed she had eaten very recently – Lundgren noted that her last meal (chicken stir fry) would have contained indigestible vegetable fibers, which would still have been visible.
Acknowledging the lack of precision about gastric timings, especially without exact knowledge of the size of the meal and its specific fat content, Lundgren also pointed out that no examination had been made of the food that may have already passed through Steenkamp's stomach and further into her digestive tract.
Wollie Wolmarans – a gruff ballistics expert with a resumé that includes stints at the UN International Criminal Tribunal for the Former Yugoslavia and in the army – testified that it was impossible with any accuracy to work out the order of the four shots Pistorius fired at Steenkamp through a locked bathroom door.
"I can't say with certainty what the position of the deceased was, at the time when the shots were fired," he told the court.
Having conducted replica ballistics tests of his own on Pistorius' pantry door, with a Beretta handgun – similar to the athlete's 9mm Taurus – and appropriate rare bullets, obtained with some difficulty, he said Steenkamp's arm appeared to be between 6 to 20 centimeters from the door when struck, but he was reluctant to speculate about her exact location when she received her other injuries.
Based on splinter distribution around Steenkamp's bullet wounds, the defense has been keen to demonstrate that Steenkamp was close to the wooden door – and unafraid of her boyfriend.
Pistorius flinched as Wolmarans described the "mushrooming" effect of Ranger ammunition as it strikes soft tissue, cradling his head in his hands as the ballistics expert spoke of Steenkamp's injuries.
During the state's case, prosecution ballistics expert Chris Mangena presented his projected bullet order with confidence – he claims it was either the third or fourth bullet that did the most damage – but Wolmarans questioned his analysis, suggesting that small deviations in the point of fire and marginal deflection by the door – which Mangena did not take into account – could change things.
He also said repeated insertion of probes, as used by the police forensic team, through the bullet holes would also affect accuracy.
Seemingly, the only certainty can be found in the physical workings of Pistorius' semi-automatic shotgun. "[To fire] each time you have to pull the trigger," Wolmarans explained.
"Can it be done rapidly?" asked Roux.
"It all depends on your reflexes," the expert replied.
It is a subject that will undoubtedly be tested by Nel in cross-examination, as much of the defense's case rests on the assumption that the athlete fired in quick succession – and in fear.
PISTORIUS: SINCERELY SORRY?
In a surprise move by the defense, Roux called the social worker who chaperoned Pistorius in the aftermath of the shooting, tasked with providing emotional support to the distraught murder-accused.
Yvette van Schalkwyk only came forward wanting to testify this last Tuesday, seemingly in an attempt to refute allegations made by a local gossip columnist that the Paralympian's courtroom emotions were the product of acting classes.
In the Pretoria holding cell where she first met him, Van Schalkwyk says she found an emotional man. "I miss Reeva so much," were his first words to her, she told the court.
"I saw a heartbroken man; he talked to me about what they planned for the future, the thought that he was never going to see her again," she said. He was concerned for Steenkamp's family, and cried 80 percent of the time, Van Schalkwyk testified.
He vomited twice then and was crying and crying, Van Schalkwyk said. "I had to get up and calm him down."
The social worker said Pistorius later told her he had "accidentally" shot his girlfriend – something Nel pounced on in cross-examination, seeking to show that the murder-accused had since changed his story, from accident to self-defense.
"He said, 'I'm sorry,' " Van Schalkwyk told the court.
But he didn't say, "I'm sorry for what I did, did he?" Nel pressed.
"No," she admitted, "but then, I didn't want to talk about the merits of the case."
Appearing to disregard her 24 years of experience as a social worker, Nel pointed out that Van Schalkwyk had no prior experience of dealing with an adult murder-accused in the immediate aftermath of a crime.
"What would you expect from someone who shot and killed someone?" he asked, eyebrows raised, suggesting that Pistorius' highly emotional state was no proof of honesty.
The Paralympian appeared to show strain Thursday, grim-faced in the dock by the end of the day, embraced by his sister Aimee and brother Carl.
The defense expects to wrap up its evidence by May 13, three days ahead of the scheduled court time for the trial.
Ballistics expert Wolmarans returns to the stand Friday.