Oscar Pistorius has given graphic details about the night he killed his girlfriend - breaking down as he revealed he can still "smell the blood".
The Paralympian is days away from returning to jail after his original conviction of culpable homicide over the death of Reeva Steenkamp was overturned.
He has now given his first television interview about what he says happened on the night he shot the 29-year-old model at his home in Pretoria, South Africa.
It comes just days after a psychologist told a South African court the Paralympian was "anxious and depressed" and too ill to give evidence at his sentencing.
In an interview with ITV, the 29-year-old sobbed as he gave his version of what happened on the night of February 14, 2013.
"I did take Reeva's life and I have to live with that," he said.
"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. 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? I think, how could this have happened? How could this have happened?"
In 2014 Pistorius was found guilty of culpable homicide - similar to manslaughter in British law. But he is now due to be sentenced for murder - a charge which carries a minimum tariff of 15 years.
He was jailed for five years but, in October 2015, was released into house arrest after serving a fifth of his sentence.
Then in December 2015, the culpable homicide verdict was overturned by South Africa's supreme court, following an appeal by the prosecution.
In Oscar Pistorius: The Interview, the former Paralympian speaks to investigative journalist, Mark Williams-Thomas about the night of Ms Steenkamp's death.
He was interviewed at his uncle's home, where he is living while awaiting sentencing, which is expected to be delivered later this month.
The Steenkamp family were asked to take part in the programme, but declined, according to ITV.
Pistorius told how he and Ms Steenkamp had gone up to bed and how he had taken his prosthetic legs off.
Before going to sleep he said he told his girlfriend: "listen if I fall asleep would you mind just closing the doors and switching off the telly?".
He then woke at about 3am and claimed he heard a "sliding noise of the window frame hitting the frame" coming from the bathroom and that the building was "pitch black".
Pistorius said he "immediately got panicked" believing it to be an intruder.
"This instant fear comes over me that there's somebody in the house. Somebody's was actually in the process of breaking in. And my first thing was thinking that I need to grab my firearm.
"If this person has already got into the house this window's already reopen, it's a matter of seconds before they're in the bedroom.
"And I'm scared; I'm terrified and I get my firearm and I say to Reeva, I said, 'call the police and get down on the floor. Call the police and get down on the floor'. But I'm still whispering at this stage.
"The first thing was thinking that I need to grab my firearm
"Basically on one of my hands, both my stumps and pointing the firearm. So I'm low down and I'm starting to shake and sweating and become.. Overcome with fear.
"And at that point I just entered into the passage and I start shouting and I start screaming get the f**k out of my house. Get out of my house. And I start screaming. And the more I start screaming the more scared I'm actually getting. The more like... the more, the more real this is feeling."
At this point, he claims, he heard the toilet door slam and believed there was someone "right here, round this corner".
"I don't have time to get my legs back on, these people are definitely in the house already, if they come at me quick enough and they grab the gun or if I hesitate, they can use the gun on, on, on either of us."
He said he shouted out "Reeva call the police" in a bid to "intimidate this person, to get out of the house".
"I'm petrified at this point I don't want to stick my arm out if they can grab my arm, I just don't have the balance to align the firearm," he said.
"At this point I see the windows open. These things are running through my head...the window has just been opened, the door has just slammed. It's the middle of the night. Reeva is right next to me in bed.
"I've got to stand there until we get help; until somebody comes, because I can't go back to Reeva and then expose her and expose myself. I'm hiding behind the toilet entrance wall. I can see the toilet door - I don't know if it's one person. All I know is there's somebody in my house. And all of a sudden I hear a noise, at the toilet. I presumed it was the toilet door opening and before I knew it I'd fired four shots."
He said the echo from the gun shot in the bathroom was "so loud" that he couldn't hear anything and that he was shouting for Ms Steenkamp to call the police and for her to get out of the house.
At that point, he claims, he walked back to his bed but could not find his girlfriend.
"I get down to the floor and I can't feel her," he said. "So I start pulling everything apart and I start saying like, 'Reeva, Reeva Reeva' and I'm like pulling my hand and I'm on my stumps now still, I was like pulling my hand across the curtain, thinking like 'Lord please tell me she's hiding behind the curtains'. And I get to the end of the curtains and my heart just sinks.
"I'm still scared that there's an intruder in the house but I'm now mixed with another fear. So I rush on my stumps back as quick as I can to the bathroom, and I've still got the firearm pointed at the door. It's locked. And I realise there is somebody inside there and they're not answering me."
He said it was at this point that he became concerned it was Ms Steenkamp in the bathroom and started trying to force open the door.
Pistorius claims he went to fix his prosthetic legs on before returning in a bid to force his way in.
"I'm screaming now for Reeva and just start screaming 'Jesus please God, please please please please please just don't let this be what I think it is'.
"I need to get in this toilet to see if it's Re. And if she's not answering why isn't she answering me, is she scared? Is she okay? So I ran back to the room down the passage to get the cricket bat and I start smashing down this door. I reach into the door to open the lock from the inside and I realise the key isn't there. And I punch, I take one of the planks that's now lose and I rip it out and then I can see Reeva is on the floor."
Starting to sob, Pistorius added: "I opened the toilet door and immediately when I saw Reeva she was over the toilet. She's.. she'd slumped over the toilet. And I... at that point I knew that I'd killed her. I knew that she was dead. And I went down on my knees and pulled her onto me."
He said he put her on the bathroom floor and then rested her head on a towel.
"I just see blood and it's just blood everywhere. It's just blood everywhere... So much blood. And I don't know what to do. I try and pick her up. I'm trying to pick her up but there's so much blood I can't stand up.
"And I thought Reeva had started breathing, so I had my fingers in her mouth and I was trying to give her mouth to mouth, but there was so much blood."
Later in the interview, he revealed how mutual friends "don't speak to me any more" but that he sees "the pain it's caused (Ms Steenkamp's) family and I don't blame them".
Attempting to describe how the situation arose, he added: "Reeva must have just gone to the bathroom. To relieve herself. And when I started shouting.. she must have thought there was somebody coming in the passage off the balcony.
I will 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.
"So she got scared and she closed the bathroom door and yet I'm thinking this is a confirmation of there being somebody in the bathroom. She just hears me shouting and me coming closer and closer to the bathroom;
"I don't know, you can ask yourself a million times, why, why didn't I just close the door before I went to bed? Why didn't Reeva close the door? Why when she got up to go to the toilet just tell me?
"Why didn't she shout at me from the toilet and all these things. I can't say, why did she do them, she didn't do anything wrong. But it's difficult. It's difficult to know if one of those small things didn't happen that the situation would be different. And I would still have her here with me."
He said that what he had done was "terrible" adding: "At times I don't feel like I should have the right to live for taking somebody else's life."
"What is difficult is dealing with this charge of murder," he said.
"The day before we started the trial on March 2 2014 I sat with my lawyers and I said to the, whatever happens I will spend - the maximum for culpable homicide is 10 years - I said to them, 'I will 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 go back to jail; I don't want to have to waste my life sitting there. If I was afforded the opportunity of 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 upon me that she would want me to live that life."
Forty-three South Island co-ed principals have asked the national body to intervene.