Kim Martin spoke on the fourth day of the sentencing portion of the double-amputee Olympian's trial. Following the testimony, which is expected to end this week, Judge Thokozile Masipa will rule on what punishment Pistorius must serve after convicting him of culpable homicide for shooting Steenkamp through a toilet door in his home.
"My lady, I really believe the accused, Mr. Pistorius, needs to pay for what he's done," Martin testified before the red-robed judge.
"My family are not seeking revenge," Martin said. "We just feel to take somebody's life, to shoot somebody behind the door who is unarmed, who is harmless, needs sufficient punishment."
Pistorius was acquitted of murder for the Feb. 14, 2013 killing and found guilty of the lesser crime of negligent killing. Masipa has wide latitude when deciding on a sentence for culpable homicide, and could order a suspended sentence and a fine, house arrest, or send him to prison for up to 15 years.
Defence lawyers have argued for a sentence of three years of house arrest with community service. In the first part of the sentencing hearing, they called a psychologist and social workers, who said that Pistorius should not go to prison because of his ongoing emotional suffering. They also said his disability as a double amputee who needs prosthetic legs would leave him vulnerable in jail.
Chief prosecutor Gerrie Nel has called suggestions of a house arrest sentence as "shockingly inappropriate" and wants Pistorius to be sent to prison.
Martin, the cousin, said a prison sentence would be appropriate for Pistorius and that she understood the rehabilitation program in jail to be humane and dignified, contrary to allegations by one of the social workers who testified for the defence. In her sometimes emotional testimony, Martin said many people had suffered because of Pistorius, including his own family, and that a sentence that excludes jail time would encourage the athlete to "feel within himself that what he's done is all right."
Zach Modise, the acting national commissioner for correctional services, testified after Martin, saying that the South African prison system compared favourably with prisons he had visited in Britain and the United States. He acknowledged problems such as overcrowding and gang activity, but said officials had made progress in combatting those problems and that some prison facilities can cater to disabled criminals, including Pistorius.
"We will be able to accomodate him," Modise said.
However, defence lawyer Barry Roux referred to reports of an increase in alleged torture in South Africa's prison system. He also said an imprisoned gang leader allegedly said Pistorius would be under threat if he is incarcerated; Modise said he was not aware of any threat.
At the beginning of Thursday's proceedings, Nel congratulated Judge Masipa on her birthday and people in the courtroom applauded. Masipa smiled, thanked Nel and then the testimony began on the 47th day of proceedings in the case, which began more than seven months ago.
Pistorius could serve 10 years in prisonASSOCIATED PRESS
Pistorius could receive a suspended, or part-suspeded sentenceASSOCIATED PRESS
Pistorius could receive a non-custodial sentenceASSOCIATED PRESS
He could be fined, and releasedChristopher Furlong via Getty Images