"It's time you look at it", he added, urging him to take responsibility for taking Ms Steenkamp's life. A sobbing Pistorius turned away from the television screen and told the court he was "tormented" by the events that took place in the early hours of 14 February.
He added: "I've taken responsibility, but I will not look at a picture where I'm tormented by what I saw and felt that night. As I picked Reeva up, my fingers touched her head. I remember. I don't have to look at a picture, I was there."
Prosecutor Gerrie Nel referred to a video of Pistorius shooting a watermelon at a firing range where the athlete is overheard saying: "It's softer than a brain, but f**k it's a zombie stopper" Mr Nel also demanded the athlete openly admitted he shot and killed his girlfriend. The prosecutor insisted her death wasn't just an "accident" and asked him to repeat the words: I shot and killed Reeva Steenkamp in one of the most dramatic scenes yet.
"You killed Reeva Steenkamp, didn't you?" he asked at the start of questioning. "You made a mistake? You killed a person. You killed Reeva Steenkamp. Say it. Say I shot and killed Reeva Steenkamp."
"I did, my lady," Pistorius tearfully replied.
Mr Nel accused the athlete of "not listening" to his questions and telling the court well "rehearsed answers" over and over. Pistorius told the court he was telling the truth and was under pressure because his life is "on the line".
"Please answer the questions, don't argue the case," Mr Nel warned. "You will get into trouble."
After the aggressive start to his cross-examination, Mr Nel began to poke holes in Pistorius's bail statement where he claimed police contaminated the crime scene and tampered evidence.
Pistorius insisted that "things were moved".
In a new development, the athlete told the court his bail application had wrongly stated he went onto his balcony to collect a fan. Today, he told his murder trial he grabbed a fan that was on the balcony.
He added: "I never went onto the balcony. I got the fan that was on the balcony. I admit that it is incorrect that I went onto the balcony. I collected the fan from the balcony."
An emotional Pistorius insisted he never intended "to kill Reeva, or anyone else" and discharged his firearm in the belief that an intruder was coming out to attack him. He was scared and wasn't wearing his prosthetic legs.
"I went to the bathroom so I could put myself between what I perceived was danger and Reeva. To approach in the time I did, I didn't have time to think. I was dealt with a set of circumstances that I was trying to deal with."
Earlier in his evidence, Pistorius described the dramatic moments that followed the shooting, after he realised he had shot Ms Steenkamp through a locked toilet door, in what he claims was a case of mistaken identity.
Pistorius told Pretoria's High Court that he put his hand on her hip, where she had been shot, to stop the bleeding and placed his fingers on her mouth to help her breathe.
The athlete told the court Ms Steenkamp died in his arms.
Pistorius said he felt helpless and that he wanted to take her to a hospital, but a neighbor advised him to wait for paramedics to arrive at the Silver Woods estate.
"The paramedics arrived. They asked for some space to work so I stood up," he said. "Reeva had already died while I was holding her, before the ambulance arrived, so I knew there was nothing they could do for her."
Police arrived at the scene soon after.
"Every time I looked up there were more people in the house. There were more policemen. There were people going up and down the stairs. I was standing in the kitchen.
"I asked a policeman if I could wash my hands because the smell of the blood was making me throw up," Pistorius said. "Every time I saw Reeva, I got sick. So I stayed inside the kitchen. I sat in the pantry against the washing machine."
He was then told to go to the garage and later told he was under arrest. Police advised him to keep his head down while exiting the house because there was "a lot of media" waiting for him.
Yesterday, Pistorius sobbed uncontrollably as he described the moment he realised Ms Steenkamp wasn't in bed and smashed down the toilet door to reach her. By the time Pistorius entered the toilet, Ms Steenkamp "wasn't breathing".
He told the court he feared an intruder had entered the house after hearing the sound of a "window sliding open". Pistorius told the court he asked Ms Steenkamp to call the police immediately.
He then heard the sound of a door slamming shut, which he said convinced him an intruder was already inside his bedroom and shot at the toilet door four times using his 9mm pistol.
Prosecutors argue he intentionally shot and killed the 29-year old model following a domestic dispute.
There are no juries at trials in South Africa and Pistorius's fate will ultimately be decided by Judge Masipa, assisted by two assessors.
The case continues.