South Africa’s supreme court of appeal on Tuesday heard arguments from state prosecutors that athlete Oscar Pistorius should be convicted of murder instead of culpable homicide. The prosecutors said that judge Thokozile Masipa was wrong last year when she ruled that Pistorius was not guilty of the murder of his girlfriend Reeva Steenkamp in 2013.

The 28-year-old was released from prison last month and placed under house arrest after serving 12 months of his five-year term for culpable homicide. The Olympic and Paralympic athlete had shot Steenkamp through a bathroom door after mistaking her for an intruder. He could be sent back to jail if the appeal judges overturn the original verdict.