“Prosecutors argued that Judge Thokozile Masipa misinterpreted a complex South African standard defining a technical form of intent that proved to be a central aspect of the case,” Legal Analyst Kelly Phelps was quoted as saying by the news channel.
Prosecutors had originally sought conviction on more serious charges of murder but the judge found Pistorius guilty of the lesser charge of culpable homicide, akin to manslaughter in other jurisdictions, which presumes the absence of intent.
The case now goes to the Supreme Court of Appeals in Bloemfontein, which will hear the appeal.
Pistorius, a South African Paralympic champion, shot his girlfriend Reeva Steenkamp dead through a closed toilet door at his home in Pretoria on February 14, 2013. He claimed he mistakenly shot Steenkamp, thinking she was an intruder.
On February 19, 2013, a Pretoria prosecutor charged Pistorius with premeditated murder. In September, Pistorius was found guilty of culpable homicide but was cleared of premeditated murder by Judge Thokozile Masipa in a ruling that many found unjust, including the Steenkamp family.
Pistorius is a double-amputee sprinter and a six-time Paralympic champion who has also taken part in able-bodied competitions. He won a silver medal in the 4x400 meter relay at the 2011 world championships.