Oscar Pistorius Sentencing Date: Ahead of Oct. 13 Hearing, Focus on Phone Call to Ex Prior to Shooting Steenkamp

Did the call made by Oscar Pistorius to one of his former girlfriends have anything to do with the action he took a few hours later when he shot his girlfriend Reeva Steenkamp inside their home in Pretoria, South Africa, on Valentine's Day this year?

The question arose just days before the South African Olympic and Paralympic sprinter faces the court again to receive his sentence on Oct. 13 following his conviction of culpable homicide for the death of Steenkamp.

Pistorius' fate will solely be in the hands of Judge Thokozile Masipa who will decide on his sentence, ranging from a maximum of 15 years in prison to no time in jail. The jury system does not exist in South Africa.

The families of both Pistorius and Steenkamp are expected to attend the culmination of the trial. The proceedings are expected to last for several days as both parties give their arguments on whether to give Pistorius a lighter or heavier punishment.

While the countdown has begun for the sentencing, a new book came out claiming that certain pieces of evidence were not brought up by the prosecution during the trial. In "Behind the Door: The Oscar Pistorius and Reeva Steenkamp Story," authors Barry Bateman and Mandy Wiener claimed that Pistorius had talked to Jenna Edkins, his former girlfriend, on the phone a few hours before he fatally shot Steenkamp inside the bathroom of their house.

The authors, who are both Eyewitness News journalists, said they found out that Pistorius talked to Edkins for nine minutes at 6 p.m. on Feb. 13. Pistorius shot Steenkamp at 3 a.m. the next day. The journalists said this was a key piece of evidence that was not brought up during the trial.

Pistorius allegedly saved Edkins' number in his phone as "babyshoes."

The book authors said the police and prosecutors were not able to include the evidence in court simply because Edkins' phone was registered under her father's name.

Another reason for this, they said, is that Carl, Oscar's older brother, had tampered with the suspect's phone right after the shooting.

Carl allegedly deleted call logs and WhatsApp messages that were supposedly incriminating.

However, the Pistorius family denied the alleged tampering.

Asked by reporters about her involvement in the case, Edkins kept silent, reports said. But she admitted that she and Pistorius dated on and off for five years starting from 2008, and that her friendship with Pistorius was common knowledge even after their breakup.

A source said the defense knew about the phone call and was ready to present Edkins on the stand should the prosecution use the evidence as a "smoking gun."

Following the revelation, some people are asking whether or not such evidence would have

influenced Judge Masipa's final verdict on Pistorius.

Based on the judge's dismissal of all arguments pertaining to the couple's relationship, legal luminaries say the call would have little effect on the final verdict of culpable homicide.

During the trial, Masipa dismissed the text messages between Steenkamp and Pistorius, saying, "Normal relationships are dynamic and unpredictable most of the time, while human beings are fickle."

The judge added: "None of the evidence of a loving relationship, or a relationship turned sour, can assist this court."