A young surfer who was stabbed as he prepared to enter the water in a "senseless" act of violence might have been the victim of a robbery gone wrong.
Kye Schaefer was stabbed multiple times after he arrived at a Coffs Harbour beach on the NSW Mid North Coast on May 2.
The injured 21-year-old was found in a car park and died after being rushed to hospital.
More than a month later, a 36-year-old man was arrested at a local prison on Tuesday and charged with Mr Schaefer's murder.
Matthew Willacy was refused bail when his case went before Coffs Harbour Local Court.
He is set to reappear at the same court on August 13.
Homicide Squad commander Danny Doherty said Willacy was known to police and believed to be living rough.
He confirmed Willacy had been charged over an unrelated robbery about the same time, not far from where Mr Schaefer was attacked.
Detective Superintendent Doherty told reporters the attack on Mr Schaefer was "an iniquitous, senseless act of violence".
"It may be a robbery gone wrong but it was unprovoked and it was violent," he later told Sydney radio 2GB.
"He's gone to the surf with his wetsuit and he's putting that on and whatever happened between the interaction between this 36-year-old man and Kye it's resulted in him being stabbed multiple times.
"He didn't get to do what he loved and unfortunately his life was taken."
NSW Police have appealed for help to find the knife used in the attack, as well as a bicycle his alleged killer was riding at the time.
Det Supt Doherty said police had a strong circumstantial case to pursue a murder charge based on CCTV footage, witness statements and forensic evidence.
Mr Schaefer's parents had previously appealed for whoever was responsible for the stabbing to come forward and "own up to your mistakes".
The victim has been described as a keen athlete and skilled soccer player, who would be profoundly missed by his friends and family.
"They're obviously still grief-stricken and their hearts are torn apart," Det Supt Doherty added.
