Following extensive investigations, homicide squad detectives on Tuesday arrested a 44-year-old man and charged him with murder.
Officers also searched the man’s home and seized mobile phones, a laptop, drugs and two prohibited weapons.
Police will allege in court the man deliberately drowned Mr Copo-Horton in the bathtub.
Refused bail, the 44-year-old will appear at Parramatta Local Court on Thursday.
Homicide squad commander, Superintendent Scott Cook said his investigators never gave up on the case.
“Today, five years on from the initial police response, we have now put a man before the courts,” he said.
“The public can be assured that the Homicide Squad, working with local police and the community, will always seek justice for victims of homicide.”
Mr Copo-Horton’s family said the five years since his death had been difficult.
“Stevie was so full of life; always happy and full of hugs and kisses,” the family said in a statement.