Oscar Pistorius has walked in court on his stumps, at the request of his lawyer Barry Roux

Oscar Pistorius walked on his stumps in a South African courtroom on Wednesday as part of his defense team’s argument that the double-amputee athlete, convicted of murdering girlfriend Reeva Steenkamp, is a vulnerable man who deserves leniency when he is sentenced.Defense lawyer Barry Roux asked Pistorius to remove his prostheses, and the former track star then hobbled in front of Judge Thokozile Masipa, who will deliver the sentence after hearings end this week. He appeared unsteady at times, and the demonstration drew gasps from some onlookers in the courtroom.

The former track star, who had changed from a suit into athletic clothes for the demonstration, then returned to a bench where he sat alone, head bowed.

Pistorius was on his stumps when he fatally shot Steenkamp through a toilet cubicle door in his home 2013; he testified at his murder trial that he felt vulnerable and thought an intruder was in the house. Prosecutors have said Pistorius intentionally killed Steenkamp after an argument.

Chief prosecutor Gerrie Nel later spoke, countering the defense argument that Pistorius is a “broken man” because of the grief from killing Steenkamp and the trauma that followed as the world focused on his case. Nel referred to the emotional testimony a day earlier of Barry Steenkamp, father of the victim.

“If you ever want to talk about a broken man, we saw a broken man there,” Nel said of Barry Steenkamp.

Pistorius is currently living under house arrest after initially serving one year of a five-year prison sentence for manslaughter for shooting Steenkamp multiple times in 2013. That conviction was overturned last year by an appeals court, which convicted Pistorius of the more serious charge of murder.

Masipa, who initially acquitted Pistorius of murder, will decide the new sentence. The hearing is scheduled to run through Friday this week. South Africa has a minimum sentence of 15 years in prison for murder, although a judge can reduce that in some circumstances.