(CNN) A South African court has refused Oscar Pistorius' request to appeal his murder conviction in the 2013 death of his girlfriend, a representative of his legal team told CNN on Thursday, clearing the way for an April sentencing.
The decision comes two months after a different court overturned his 2014 conviction of culpable homicide and instead found him guilty of murder.
South Africa's Constitutional Court refused Pistorius' application to appeal the December ruling, saying that his appeal would have no realistic prospect of success, the legal team representative said.
Pistorius is scheduled to be resentenced on April 18. He faces up to 15 years in prison.
The double-amputee sprinter initially was sentenced to five years in prison for culpable homicide. He served a year of that sentence in prison before being transferred to house detention.
After South Africa's Supreme Court of Appeal overturned the initial conviction and found him guilty of murder in December, he was released on bail, with the stipulation that he wear an electronic monitoring device and travel only a limited distance from home between 7 a.m. and noon.
The Olympian shot girlfriend Reeva Steenkamp, a model, four times through a locked toilet door on Valentine's Day in 2013, saying he mistook her for an intruder.
in December, Judge Eric Leach ruled the original court judgment had been "fundamentally flawed." The Paralympic gold medalist should have foreseen that his firing of a gun would have killed whoever was behind the door in his bathroom, regardless of whether he thought it was Steenkamp or an intruder, the judge ruled.
Prosecutors had argued that the 29-year old -- known as the "Blade Runner" in a reference to the prosthetic legs he uses when he races -- intentionally killed Steenkamp after an argument.
Leach said that although Pistorius had genuine beliefs that his life was in danger, he should have acted more rationally.
He never fired a warning shot and shot not once, but four times.
"The identity of victim is irrelevant to his guilt," he said.
CNN legal analyst Kelly Phelps said late last year that double jeopardy -- a defense that prevents a criminal defendant from being retried on the same charges after a verdict -- did not technically apply in the Pistorius' case for two reasons.
First, Pistorius wasn't completely acquitted on the original charge but had been convicted of culpable homicide.
"Strictly speaking, because murder wasn't a separate charge but was tied in with the culpable homicide charge, it's not considered technically ... as reconsidering a case where there has been a complete acquittal," said Phelps, a senior lecturer in law at the University of Cape Town.
The second reason, she said, was that the appeal "was based on a question of law, not a question of fact."
"The argument is that where there's been a mistake in law that's been made -- that is the only reason that an incorrect verdict has been reached -- it would be offensive to the interests of justice in order to allow that verdict to stand," she said.