Reeva Steenkamp's mother June Steenkamp has said she could not take take her eyes from Oscar Pistorius as he described her daughter's death in his trial, to see if he was faking his emotional reactions to recounting what happened.
She spoke of her daily emotional turmoil as she listened to the final moments of her daughter's life being put under the spotlight in the trial. The Paralympian denies murdering Reeva Steenkamp, saying he shot her after mistaking her for an intruder on Valentine's Day 2013.
Pistorius has frequently wept and been sick during the more difficult moments of his trial but Mrs Steenkamp said she watches his every move, wondering if his grief is real.
In an interview with the Daily Mirror, she said: "I look at Oscar the whole time, to see how he is coping, how he is behaving. I'm obsessed with looking at him, it's just instinctive, I can't explain it.
"I keep thinking, 'let's see how he's taking this'. He has been very dramatic, the vomiting and crying."
She added: "I think he's just about keeping himself together. I don't know whether he's acting. Most of the time he's on his cell phone or looking down at papers or writing notes."
Mrs Steenkamp said Pistorius had fallen from "hero to devil", and said she was determined to maintain her own composure, despite harrowing images of her daughter's body being shown to the court.
On Wednesday, Pistorius, 27, became distraught after the prosecutor demanded that he look at a photo of his dead girlfriend's bloody head wounds while giving evidence at his trial in Pretoria.
Prosecutor Gerrie Nel said it was time for the athlete to "take responsibility" for killing Steenkamp, 29.
Mrs Steenkamp said she and her husband Barry were tortured by their feelings of helplessness at what their daughter went through, saying it "haunts" her that they couldn't help her and that her death has "destroyed" their lives.
She added: "I imagine how she must have been in terror and pain and suffering, devastated by what was going on. I relive that scene in the bathroom and it's changed me so much, made me harder."
Mrs Steenkamp, who had never previously met Pistorius, told The Mirror she doesn't care if he is cleared or sent to prison as it won't bring back her daughter but added: "He has to stand up to what he's done and - if he has to - pay for it."
She said Pistorius has an "aggressive persona" and struts around looking "superior" but now "he's gone from hero to devil".
Mrs Steenkamp also told The Mirror she cried after Pistorius apologised for killing her daughter but only because it reminded her of Reeva's suffering and that she would never see her again.
She also said she had rejected efforts by his family to apologise and reach out to her.
Mrs Steenkamp previously criticised Pistorius for failing to acknowledge her on the first day of the trial but said she didn't answer when he eventually spoke to her, other than to nod.
She said she believed her presence "unnerves" him, saying: "He must see me there in the court, he must feel my eyes boring into him, I think it makes a lot of difference.
"I do look at him too much, maybe. I like to see how he is reacting. I can see him very clearly, even without my glasses - he's the only one I can see, he's right in front of me."
Despite being "wiped out" by a particular photograph of her daughter that was shown to the court, Mrs Steenkamp said she was "compelled" to be there, and was determined to keep her emotions in check until she is alone.
She said: "I'm being strong for Reeva, I have to be there. It's hard for me to do it, but I'm representing my child."
Mrs Steenkamp's husband Barry has been kept away from the trial by ill-health, having suffered a stroke, but has vowed to join his wife in the courtroom.
Pistorius will face further difficult questions today as his cross-examination continues.