PRETORIA, South Africa — Oscar Pistorius was taken away in a police van Tuesday to start serving a five-year prison sentence for killing girlfriend Reeva Steenkamp.

A South African judge cited the “gross negligence” the Olympic runner showed when he shot Steenkamp multiple times through a toilet cubicle door in his home when she delivered the sentence. Pistorius' prison term begins immediately.

Pistorius could be released after 10 months in jail to serve the remainder under house arrest, according to legal experts.

Masipa also sentenced Pistorius to three years in prison for unlawfully firing a gun in a restaurant in a separate incident weeks before Steenkamp's 2013 shooting death. She ordered that sentence to be wholly suspended for five years on condition that Pistorius is not found guilty of another firearm offense.

Masipa delivered her ruling after reviewing prosecution arguments for a tough sentence as well as the defense case for a more lenient punishment for Pistorius. She said it was a balancing act after defense lawyers had argued that Pistorius had already suffered emotionally and financially after what he called an accidental killing.

Masipa last month convicted Pistorius of culpable homicide, but acquitted him of murder after he testified he mistook Steenkamp for a nighttime intruder.

“The following is what I consider is a sentence that is fair and just both to society and the accused,” Masipa said as she announced her decision.

She asked Pistorius to stand as she delivered the sentence, and the world-famous disabled runner faced her with his hands clasped in front of him.