A man was stabbed to death and a teenager severely injured at the Weston skatepark in the early hours of Sunday morning.
Police were called to the scene around 1am on Sunday, where they found an 18-year-old man and a 16-year-old boy with stab wounds.
Both were treated by paramedics but the 18-year-old died at the scene. The teenager was transported to the Canberra Hospital with severe injuries and will require surgery.
ACT Policing's detective acting superintendent Mark Steel said police were treating the incident as a suspicious death and the homicide squad had been called in.
He could not confirm if a weapon had been found but said the AFP Forensics unit was at the site examining the area.
It was being investigated whether the two males knew each other, but acting superintendent Steel said he believed they were at the scene together and it was possible other people were involved in the incident.
The incident occurred next to the skatepark, opposite the Weston Creek McDonalds and behind the tennis courts. Police had cordoned off the whole of Dillon Close and protective barriers had been placed around the 18-year-old's body.
A police search and rescue unit was due to comb the area for evidence later on Sunday and the area would remain cordoned off for at least the rest of the day.
Distressed family members of the 18-year-old victim were at the scene looking on.
No arrests had been made and acting superintendent Steel called on any members of the public with information to come forward to police.
"We're currently investigating and examining CCTV footage. If any residents of Weston, certainly in the area of Dillon Close have any information or CCTV that they could provide to police that would be welcome," he said.
Acting superintendent Steel said the stabbing was reported to 000 requesting police and paramedics at the scene. It was at this stage unknown who made the 000 call and he asked for anyone who may have been at the scene and called emergency services to come forward.
Information can be provided to CrimeStoppers anonymously by calling 1800 333 000.
In a Facebook post the Weston Creek Tennis Club announced that it would be closed on Sunday and no tennis, including the Junior Open, would go ahead.
It indicated it may have to remain closed on Monday as well and would notify the community and suggested people should not attempt to book courts online.