Pistorius has prison sentence more than doubled to 13 years, 5 months

Former Olympic athlete Oscar Pistorius had his prison sentence lengthened significantly, from six years to 13 years and five months, by South Africa's Supreme Court of Appeal on Friday.

The court upheld an appeal by prosecutors against Pistorius' original sentence for shooting and killing his girlfriend Reeva Steenkamp in February of 2013. Pistorius claimed he'd mistaken Steenkamp for a home invader, and was initially convicted of manslaughter. The conviction was overturned by the Supreme Court and replaced with a murder conviction in 2015.

In the appeal, prosecutors argued Pistorius was getting off too easy with the six-year sentence. In their ruling Friday, the Supreme Court agreed, writing "the sentence of six years' imprisonment is shockingly lenient to a point where it has the effect of trivializing this serious offence," according to the Associated Press.

The court added Pistorius "displays a lack of remorse, and does not appreciate the gravity of his actions."

The 31-year-old double amputee, who has served a year and five months of his sentence to date, would have been eligible for parole in 2019. The revised sentence means the earliest he can now be released is 2023.