WATCH: Oscar Pistorius Cries While Speaking Out About Girlfriend's Death: 'I Did Take Reeva's Life, and I Have to Live with It'

Oscar Pistorius says he's willing to accept time behind bars for what he claims was the accidental shooting of his girlfriend in 2013, but denies he's guilty of premeditated murder.

"I did take Reeva's life, and I have to live with it," the former South African sprinter and double-amputee known as the "Blade Runner" says through tears in an interview to be broadcast Saturday on REELZ, ahead of his July sentencing for killing Reeva Steenkamp. "I can smell the blood. I can feel the warmness of it on my hands. And to know that that's your fault, that that's what you've done."

"And I understand the pain people feel that loved her and miss her," he says. "I feel that same pain, I feel that same hate for myself, I feel that same difficulty in understanding this. And I look back and I think – I always think, how did this possibly happen?"

Pistorius faces 15 years in prison for the murder of Steenkamp, a model and law school graduate who was behind a closed bathroom door at his home on Feb. 14, 2013, when Pistorius says he fired his gun at what he believed to be an intruder who had broken in.

For three years, Pistorius – a celebrity at the 2012 London Summer Olympics and the first to compete on prosthetics at that level against more able-bodied runners – has stuck to his account of what happened that night.

He says he believed Steenkamp was still in bed with him when he awoke to noises in the middle of the night. In the pitch-black of his bedroom, he says he urged her to call police and hide while he grabbed a handgun, then walked on his stumps down a hall toward the bathroom shouting for the intruder to flee.

"I need to get between this intruder and Reeva, and I need to approach this person because I can't run away without my legs," he recalls. "If I sit there and wait for them, and this person comes out shooting, I needed to get to a point where I'm safe, but also where Reeva's safe, and if she's behind the bed, and I can stand at the passage and look down the passage, then at least I'm between them and her."

He adds: "Before I knew it, I'd fired four shots."

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In Sept. 2014 he was found guilty of culpable homicide, or the equivalent of manslaughter, and served one year of a five-year sentence before his release last October. But after the prosecution appealed, that conviction was overturned and he was judged guilty of murder; the appeals court concluded that no matter the identity of the person who died, Pistorius had meant to kill.

At his trial, prosecutors argued that Pistorius was irresponsible with guns. He was earlier found guilty of unlawfully discharging a firearm in a public place (a friend's restaurant). In the interview he dismisses allegations that the couple had argued that night, which the prosecution suggested had provided a motive for his actions.

"I don't argue with anyone that feels they should lock me up and throw the key away," he says. "But if their premise is based on the fact that I took her life intentionally, which has not been found, then it's a very sad thing to think that society would want to do that.

"I've only contributed positively to people's lives, I'd like to think, before this tragedy happened," he adds.

Steenkamp's family declined to be interviewed for the broadcast. After the murder conviction, Steenkamp's mother, June, told NBC, "I wanted respect for my daughter's life and that's what I got today, a conviction of murder. I feel so proud now that she's got some respect and she hasn't lost her life for nothing. She'll be remembered."

Pistorius, who has been free and living with his uncle after posting a bond, says he understands those who say he deserves to spend a long time in jail.

"I can't disagree with that," he says. "At times I don't feel I should have the right to live for taking somebody else's life."

"What is difficult is dealing with this charge of murder," he continues. "The day before we started the trial on the second of March in 2014, I sat with my lawyers and I said to them that whatever happens, I will spend – the maximum for culpable homicide is 10 years – so I said to them, 'I'll spend 10 years in jail for taking Reeva's life for culpable homicide, but I won't spend a day in jail for murdering anyone.'

"I don't want to have to go back to jail," he says. "I don't want to have to waste my life sitting there. If I was afforded the opportunity at redemption, I would like to help the less fortunate like I had in my past. I would like to believe that if Reeva could look down on me, that she would want me to live that life."

The hour-long Oscar Pistorius: The Interview premieres at 8 p.m. ET/PT Saturday on REELZ.