"It was a shock to the nation when we first heard it ... but it has worn off," he said. "We have sobered up -- even though people will still question why."
The allegation was a major fall from grace for a man who made history last year by becoming the first double-amputee runner to compete in the able-bodied Olympic Games in London.
Meanwhile, South Africa's national broadcaster aired a reality TV show featuring Steenkamp discussing her exit from the taped program, on which she was a contestant.
"I'm going home with sort of a sweet taste in my mouth. I don't have any regrets. I don't have any bitterness," she said. "I'm going to miss you all so much and I love you very very much."
The decision to air the program took "much deliberation," and that "this week's episode will be dedicated to Reeva's memory," Executive producer Samantha Moon said.
A fallen hero
When Pistorius was a toddler, his legs were amputated below the knees because of a bone defect.
He runs on special carbon fiber blades, hence the nickname.
A few weeks after the Olympics, he smashed a record to win the men's 400-meter in the 2012 Paralympic Games.
Images of his sports feats flashed across the screens at the time. But by Thursday, it was a jarringly different story.
Pictures of his walk to a police car, his head covered by a sweatshirt, flashed across television screens worldwide.
Then there was his court appearance 24 hours later, grim-faced and sobbing uncontrollably.
Prosecutors planned to upgrade the charge to premeditated murder.
A nation, jolted
Steenkamp's killing rattled South Africa, which is grappling with the aftermath of the recent murder of 17-year-old Anene Booyson -- a case that has put a spotlight on violence against women.
Booyson died after she was gang-raped and mutilated in Bredasdorp, a tiny tourist town southeast of Capetown.
While police have not discussed a possible motive for the 29-year-old model's killing, local media reported that Pistorius had mistaken his girlfriend for an intruder.
But South African authorities stressed that the scenario did not come from them, and said there was no evidence of forced entry at the home.
Police found her in a pool of blood before dawn Thursday after neighbors in the gated community alerted them.
Investigators found a 9mm pistol at the scene.