Police found the Villawood man suffering several stab wounds after they were called to reports of a brawl at Leonard Reserve on Chapel Street, Roselands, shortly before 9.50pm last Thursday.
He was treated by paramedics but died at the scene.
A 17-year-old who was hospitalised with a hand injury was arrested when he was discharged and charged with affray and hinder investigation serious indictable offence of other.
A crime scene was established and an investigation has begun under Strike Force Poton.
Police have been told there were numerous people involved in the fight.
Campsie Police Commander Superintendent Sheridan Waldau said it was very concerning that this type of incident could occur at a local family park.
Supt Waldau said it was believed there were eight to 10 people involved and three to four were seen running from the scene, with a blood trail leading from Chapel Street into Myers Street.
“It’s a shocking, tragic event,” she said.
“We are appealing for anybody to come forward – we know there were a number of people there at the time and we know they know what happened.”
Police are not getting much assistance with their investigation and have appealed for anyone with information or dashcam footage to contact Campsie Police or Crime Stoppers on 1800 333 000 or nsw.crimestoppers.com.au. Information is treated in strict confidence.
