Oscar Pistorius has been found guilty of murder. But this might not be the end of the saga

South African Paralympic sprinter Oscar Pistorius appears at the Magistrate Court in Pretoria on August 19, 2013. Pistorius was indicted on charges of murdering his model girlfriend Reeva Steenkamp on February 14. He denies the charge.

JOHANNESBURG, South Africa — Oscar Pistorius, the South African double amputee sprinter, has been found guilty of murder in a case described by an appeals court judge as "a human tragedy of Shakespearean proportions."

The Supreme Court of Appeal in Bloemfontein ruled Thursday that Pistorius's conviction for culpable homicide (similar to manslaughter) in the death of girlfriend Reeva Steenkamp will be replaced by a murder conviction. The case has been sent back to the trial court for sentencing.

Barry Steenkamp, Reeva's father, said after the verdict: "It's a big relief. I feel it's a fair decision that the judge gave," before breaking down in tears. 

But this might not be the end of the Pistorius trial drama. Some legal experts have raised the prospect of the athlete's lawyers appealing the case to the Constitutional Court, the highest court in South Africa, arguing that Pistorius received an unfair trial.

Pistorius, 29, shot and killed Steenkamp, a law graduate turned model and reality TV star, in the early hours of Valentine's Day 2013. His trial, broadcast live on television, gripped many South Africans and drew reporters from around the world. 

More from GlobalPost: Why the Oscar Pistorius saga is the 'trial of the century'

In a written ruling on behalf of a panel of five judges, appeals court Justice Eric Leach summarized the tragedy of the case: "A young man overcomes huge physical disabilities to reach Olympian heights as an athlete; in doing so he [be]comes an international celebrity; he meets a young woman of great natural beauty and a successful model; romance blossoms."

"And then, ironically on Valentine’s Day, all is destroyed when he takes her life," the ruling said.

State prosecutors argued during the trial and Pistorius had killed Steenkamp after a fight, but Pistorius has maintained that he believed there was an intruder hiding in the bathroom of his home.

Justice Thokozile Masipa, who presided over the trial, accepted that Pistorius hadn’t intended to kill Steenkamp, and noted that he had shown remorse almost immediately after her death.

But the crux of the appeal was the issue of intent to kill, known as "dolus eventualis" — meaning, could Pistorius have foreseen that firing four bullets through the door of a tiny toilet cubicle, with a 9mm gun, would have killed whoever was behind that door, regardless of the identity of that person.

“The accused’s incorrect appreciation as to who was in the cubicle is not determinative of whether he had the requisite criminal intent," the appeal decision said.

Leach noted "fundamental errors" in Masipa's decision regarding legal principles around the issue of intent, as well as principles regarding circumstantial evidence. He said the identity of the person behind the door — whether an intruder or Steenkamp — was irrelevant, and compared the situation to someone setting off a bomb in a public place not knowing who will be the victims.

Leach also said that Pistorius's evidence regarding his state of mind when he he fired the gun was "vacillating and untruthful." He agreed with Masipa's characterization of Pistorius as "a very poor witness," noting the shifting versions of his account.

Pistorius is currently under house arrest, at his uncle's home in Pretoria, after spending one year of his five-year culpable homicide sentence in a maximum security prison.

His family said that the athlete's legal team would be studying the decision: "We will be guided by them in terms of options going forward," Anneliese Burgess, a spokesperson for the Pistorius family, said in a statement.

State prosecutors said they will study the decision before deciding whether to seek imprisonment for Pistorius while he awaits sentencing.

While murder convictions generally carry a minimum sentence of 15 years in South Africa, the judge has the option of handing down a lesser sentence if there are extenuating circumstances.

Leach, in his ruling, noted that the trial was “attended by unprecedented publicity.”

“As far as I am aware, for the first time in the history of this country the trial was covered on live television,” he wrote.

While Leach disagreed with the legal reasoning in Masipa's ruling, he praised her manner of handling a trial "conducted in the glare of international attention."