Oscar Pistorius is preparing to return to court to learn whether he will be granted bail following the death of his girlfriend Reeva Steenkamp.
The Paralympian is charged with the premeditated murder of the 29-year-old model in the early hours of last Thursday.
Police said she was shot four times with a pistol owned by Pistorius at his home in South Africa, where she died from her injuries.
The bail hearing comes after Pistorius' former headteacher said he was "shocked" by allegations the 26-year-old had deliberately killed Miss Steenkamp, a law graduate who he had been dating for three months.
"From my knowledge of Oscar, it would have been completely out of character, and that's why I find it so hard to accept or to understand," Bill Schroder told Sky News.
"The scary thing for all of us is that they seem to want to charge him with premeditated murder.
"That's horrendous; it's the ultimate crime and carries the ultimate penalty, and I truly don't want to believe that he's capable of that."
Pistorius, who won two gold medals at the London 2012 Paralympic Games, has been held in a police cell in Pretoria since he was arrested and charged with Miss Steenkamp's murder.
His family has vowed to fight the charge in the "strongest terms" and insisted that evidence will refute "any possibility of a premeditated murder or indeed any murder at all".
Miss Steenkamp's family and friends are expected to attend an hour-long memorial service later before a private cremation in her home town of Port Elizabeth.
Her mother, June Steenkamp, told the Times of South Africa : "She had so much of herself to give and now all that is gone - just like that, she is gone.
"In the blink of an eye and a single breath, the most beautiful person who ever lived is no longer here.
"All we have is this horrendous death to deal with ... to get to grips with.
"All we want are answers ... answers as to why this had to happen, why our beautiful daughter had to die like this."