Cole Miller's father has called for more to be done to stop the kind of senseless violence that took the life of his beloved son after his killer was sentenced to seven years in jail.
New Zealander Armstrong Renata faced the Brisbane Supreme Court on Friday, having pleaded guilty to a count of unlawful striking causing death over the January 2016 assault.
The 23-year-old will be required to serve 80 per cent of the term before he can apply for parole.
Justice Helen Bowskill described the Fortitude Valley incident as "cowardly and violent" and said his actions stole the life of a young man and "destroyed" those of his family and close friends.
However, she noted it was also a tragedy that Renata found himself in the prisoner's dock because of a single moment of gratuitous violence.
"We lost our best one," Cole's father Steven said, voice wavering, outside court as he spoke of his family's loss.
He said he thought Renata's sentencing was professionally and ably handled, but called for greater deterrents to stem a tide of "senseless violence" plaguing society as a whole.
"Our society is just full of violence every day and until there is a bigger deterrent I think we're not going to solve this problem," he said.
"We have a social problem with violence."
His comments came after the bereaved father gave a heart-wrenching victim impact statement to the court describing the "nightmare" of losing his son.
Mr Miller said the talented water polo player was a "kid with a dream" and his death had thrown the family into "utter turmoil".
"It's been a long 20 months since then, I know my children suffer everyday," Mr Miller said.
"(The) tragic loss of their brother ... is a burden they will carry forever."
At times dabbing his eyes with a tissue, Mr Miller described lying awake at night listening to his wife Mary-Leigh cry.
He then read his wife's statement in which she described having to take anti-depressants and sleeping tablets to cope with the devastation of her loss.
She said she was engulfed by grief whenever left alone and remembered her son as a beautiful, quiet and gentle young man.
Renata appeared distressed in the dock as he listened to the harrowing statements, later making his own apology to the court.
"From the very bottom of my heart, I am truly sorry," he said.
It comes after Renata's co-accused, Daniel Maxwell, walked from court in August after being given an 18-month suspended sentence for starting the fight that led to Mr Miller's death.
Maxwell has since been deported to New Zealand.
Renata's more than 600 days in pre-sentence custody were declared as time already served, meaning he could apply for parole in just under four years.