A South African judge ruled on Wednesday, Dec 10, that prosecutors may appeal her decision to acquit Oscar Pistorius, the track star, on murder charges in the killing of his girlfriend last year.

However, in a complex ruling, Judge Thokozile Matilda Masipa rejected efforts by state prosecutors to appeal the five-year sentence she passed on him, the New York Times reports.

The prosecution had called the sentence “shockingly inappropriate” to the crime, since Pistorius could be released on house arrest after 10 months in the hospital wing of a prison in Pretoria, the South African capital.

In September, Judge Masipa acquitted Pistorius of murder but found him guilty of culpable homicide, equivalent to manslaughter, for firing four rounds from a handgun through a locked toilet cubicle door, killing his girlfriend, Reeva Steenkamp, on the other side.

The judge’s ruling on Wednesday hinged on a distinction in South African law between culpable homicide and a form of murder when a defendant is accused of knowing that his or her actions may cause death.

On Tuesday, the state prosecutor, Gerrie Nel, argued that Pistorius must have understood the likely outcome of opening fire and that he had therefore committed a form of murder regarded as a more serious crime than culpable homicide but a lesser offense than premeditated murder, which carries a 25-year minimum sentence.