PRETORIA, South Africa — Oscar Pistorius was sentenced to five years in prison Tuesday for killing girlfriend Reeva Steenkamp, completing a transformation from an acclaimed sprinter at the 2012 Olympics to a convicted criminal led away in a police van with barred windows. Wearing a dark suit, the double-amputee athlete was subdued when Judge Thokozile Masipa announced the punishment in a Pretoria courtroom, ending a televised trial that was closely followed at home and abroad by those who once admired him. The man known as the “Blade Runner” because of his carbon-fiber running blades will have to serve 10 months, or one-sixth of his sentence, in prison before he is eligible to be moved to house arrest, legal analysts say. South Africans seemed torn between acceptance of the ruling, touted by some as an example of judicial accountability in a nation that shed white racist rule 20 years ago, and nagging concern that Pistorius received leniency because he was rich and famous.