Though no motive has been revealed, according to media commentators, Pistorius may have been caught off guard by Steenkamp. He possibly shot her in their home in South Africa, believing she was an intruder when she tried to surprise him on the special holiday.
Pistorius is a Paralympic champion and was the first double-amputee to take part in the Olympics track and field competition in 2012.
Pistorius is not the only athlete who has gotten in trouble with the law for murder.
NFL superstar O.J. Simpson was involved in perhaps history's most publicized trial, after allegedly killing ex-wife Nicole Brown Simpson and Ron Goldman. He stood trial for the double-murder in 1995 but was later acquitted.
Leonard Little, a Rams linebacker, was charged with murder for killing Susan Gutweiler after celebrating his 24th birthday. In 1998, Little got behind the wheel while intoxicated, running a red light and ramming into Gutweiler’s car.
“I think about it all the time," Little told CNN.
"I mean, every day I wake up in the morning, I think about it. It's always in the back of my mind no matter if you're at the Super Bowl or anything bigger than that. It's always there, and I always think about it."
Little was later sentenced to 90 days in a work house and 1,000 hours of community service.
A year later, former Carolina Panthers wide receiver Rae Carruth shot his pregnant 24-year-old girlfriend four times in the back. Cherica Adams was seven-months pregnant with Carruth’s child, and Carruth was not interested in paying child support due to financial issues.
Adams was taken to the hospital but did not make it. Her son, Chancellor Lee, survived, though he was born 10 weeks premature and now suffers from cerebral palsy and is confined to a wheelchair.
Carruth was found guilty of conspiracy to commit murder in 2001 and was sentenced to 18 to 24 years in prison.
In 2000, Super Bowl champion Ray Lewis, who retired after playing 17 seasons for the Baltimore Ravens, was charged with two counts of murder and felony murder after Richard Lollar and Jacinth Baker were stabbed to death outside a nightclub in Atlanta hours after the Super Bowl.
His charges were later reduced in exchange for his testifying against two of his friends, Reginald Oakley and Joseph Sweeting.
Lewis was later fined $250,000 by the NFL and served one year of probation.
Back in 2002, Former New Jersey Nets star basketball player Jayson Williams was charged with "reckless manslaughter" in the shooting death of limo driver Contas Christofi. He was found guilty and served an 18-month prison sentence before being released in April 2012.
In 2004, NHL player Mike Danton was charged with conspiracy to commit murder after hiring a hit man to murder his agent, David Frost. The murder was not executed as the hit man was an undercover officer.
Danton reached an agreement with prosecutors, pleading guilty to one count of conspiracy to commit murder-for-hire. He served a little more than five years in prison and now plays hockey in the Swedish Division 1 league.
Also in 2004, English footballer Lee Hughes was imprisoned for three years after being found guilty of causing death by dangerous driving. Hughes fled the scene after hitting Douglas Graham, a father of four.
"In running away, you showed a callous disregard for others who were in the other car, one of whom was dead, another of whom was seriously injured and two others who were injured. I am quite certain that in running away you were thinking of yourself and you were attempting to avoid the legal consequences of driving having consumed alcohol," the judge told Hughes after the verdict was read. Hughes now plays for the Oldham Athletics.
In 2005, former pitcher for the Detroit Tigers, Chicago White Sox and Philadelphia Phillies Ugueth Urbina was charged with attempted murder after employees at his farm said he attacked them with a machete. Urbina was sentenced to 14 years in prison and served 7 years before being released in December 2012.