SeaWorld gets killer whale after custody dispute
Dawn Brancheau died in February 2010 after the whale, named Tilikum, dragged her underwater by her hair and repeatedly struck her.
SeaWorld officials said taking part in shows was important for the 12,000lb (5,454kg) orca bull's health.
But new safety rules mean the park's trainers can no longer enter the water to perform tricks with the whales.
The trainers now stand behind metal bars at the edge of the pool, occasionally stroking the whales and hand feeding them.
Whale linked to other deaths
The park's animal training curator, Kelly Flaherty Clark, said the decision to return Tilikum to the "Believe" shows had been made in the whale's interests.
"Participating in shows is just a portion of Tilikum's day, but we feel it is an important component of his physical, social and mental enrichment," he said in a statement.
"He has been regularly interacting with his trainers and the other whales for purposes of training, exercise and social and mental stimulation, and has enjoyed access to all of the pools in the Shamu Stadium complex."
The investigation into Ms Brancheau's death ruled that she died from drowning and traumatic injuries, inflicted as she performed with Tilikum in front of an audience.
The whale has also been linked to two other deaths.
An inquest into the 1991 death of a trainer in Canada ruled Tilikum and two other whales had prevented her from leaving their tank after she fell in.
And at SeaWorld Orlando, in 1999, a 27-year-old man was found dead alongside the whale.
An inquest ruled that he had died of hypothermia, but officials also said it appeared Tilikum had bitten the man and torn off his trunks, apparently believing he was a toy to play with.
via: bbc