PRETORIA, South Africa >> Oscar Pistorius’ murder trial enters a critical phase Monday as his defense team attempts to recover from a faltering start and reinforce the disabled athlete’s claim that he fatally shot girlfriend Reeva Steenkamp by mistake because he was overwhelmed by a long-held fear of violent crime.

Pistorius’ mindset when he stood on his stumps in a bathroom and pulled the trigger on his 9 mm pistol in the early hours of Feb. 14, 2013 remains the crux of the South African trial that has captured worldwide attention and is about to start its seventh week of globally televised proceedings. It was initially scheduled to run for three weeks.

Judge Thokozile Masipa will analyze thousands of pages of testimony before she reaches a verdict, but ultimately must ponder the pivotal question: Did Pistorius fire his gun with the intention to kill or out of a misplaced belief that his life was in danger from a perceived intruder?

South Africa does not have trial by jury, meaning Masipa will decide, with the help of two assessors, if Pistorius’ overall account is believable and whether the apparent inconsistencies in his testimony count against him or are unimportant in the bigger picture.

If Pistorius’ defense, which will resume calling witnesses Monday after a two-week trial recess, can show that his story of a tragic error is a reasonable explanation, even the double-amputee runner’s shaky testimony would be rendered irrelevant and the judge should acquit him of murder, legal experts say.

While testifying, Pistorius sometimes contradicted earlier testimony and other times said he did not remember details.

“The test doesn’t end there,” former state prosecutor Marius du Toit said of Pistorius’ testimony. “It’s not over. They (the defense) can still show there is another plausible scenario.”

Du Toit has over 20 years’ experience in South Africa’s criminal justice system and is following the trial closely. He said it must be shown that Pistorius had the “sole intention” to kill Steenkamp to be convicted of murder.

Pistorius, 27, doesn’t dispute that he shot 29-year-old Steenkamp through a toilet door. He claims the killing was accidental and he fired four times in quick succession without thinking and while terrified, believing that an intruder had climbed up a ladder and through a bathroom window of his Pretoria villa in the pre-dawn hours and was about to come out of the cubicle and attack him.

Prosecutors charge that the story is an intricate lie designed to cover up a murder. They say the couple fought, Steenkamp fled to the toilet screaming and Pistorius followed her and shot her through the wood door while they were arguing. She was hit in the hip, arm and head.

Charged with premeditated murder, the first amputee to run at the Olympics faces 25 years to life in prison if convicted. He was once widely admired for overcoming the amputation of his lower legs as a baby to earn the right to run against the world’s top able-bodied athletes.

The prosecution’s case appeared to be bolstered as holes in Pistorius’ story were exposed when the athlete was on the stand for a fierce five-day cross-examination by prosecutor Gerrie Nel. Nel also succeeded in undermining the evidence given by the defense’s first two expert witnesses, a pathologist and a former police forensic scientist.

But defense lawyers have only presented three of up to 17 witnesses they say they may ask to testify. At the outset of the defense’s case, lawyer Barry Roux said Pistorius’ actions on Valentine’s Day last year centered on his “disability” and “vulnerability” and Pistorius’ team will likely seek to rebuild the overall argument that his actions were guided by fear and not anger in a country with a high rate of violent home invasions.

Roux said he will also show that a crucial thread of the prosecution’s case is not true; that neighbors heard a woman screaming before and during the shots fired by Pistorius at around 3.17 a.m. on the fatal night. The lawyer said neighbors who live closer to Pistorius’ house in an upscale gated community in the suburbs of South Africa’s capital never heard a woman scream.

Instead, it was Pistorius’ high-pitched shrieks for help after realizing his terrible mistake, the defense argues.