The Supreme Court of Appeal, in Bloemfontein, has today increased the sentence of former Paralympian and Olympian Oscar Pistorius to 13 years for that crime.
Pistorius shot, firing four times through a closed bathroom door, and killed Steenkamp, a model and law graduate, and claimed that he mistook her for an burglar on Valentine's Day in 2013 in Pretoria, South Africa.
"The sentence of six years' imprisonment is shockingly lenient to a point where it has the effect of trivializing this serious offense", he added. At the Supreme Court of Appeal, Prosecutors argued that the six-year sentence was "shockingly lenient".
Pistorius became the first amputee runner to compete at the Olympics and was even known as the "fastest man on no legs" and the "Blade Runner".
"They have sent all their love to the Ings family because they feel that although justice was serviced for Jayde, they know the Ings family will still miss Jayde every day".
The conviction was later overturned and a murder conviction was set in place in 2015.
Judge Masipa ruled that although the Steenkamps had suffered a great loss, Pistorius' life and career were also in ruins.
The accused's brother Carl Pistorius tweeted he was "shattered, heartbroken, gutted" by the ruling.
Judge Thokozile Masipa ruled the state failed to prove beyond reasonable doubt that Pistorius was guilty of premeditated murder, but may still be guilty of culpable homicide - equivalent to the United Kingdom law of manslaughter. The court agreed and the sentence is now 13 years. There is no death penalty in South Africa.
Pistorius has to serve at least half of his new sentence before he is considered for parole. He will now serve the 15-year minimum for murder in South Africa.
The athlete was originally convicted of manslaughter and sentenced to five years in jail.
Seriti said the facts of the case demanded a higher sentence.
Oscar Pistorius in his murder trail at the High Court in Pretoria on 6 July 2016.