28-year-old man died after shooting at a meeting in East London.
The police were called to Cheney Row Park, Waltham Forestaround 12:30 p.m. on Sunday to reports of shots fired.
Shortly afterwards, two men came to an east London hospital, one of whom later died of gunshot wounds.
The other man, in his thirties, had suffered stab wounds. He was later released from the hospital and has been arrested in connection with the incident.
Witnesses have been urged to remember the victim’s “mourning mother and father” and help police with their investigation.
Residents near Cheney Row Park said they expected problems when they saw groups arriving in the area.
One man, who declined to be named, said: “We live around the corner so we haven’t seen anything, but I’ve seen more and more kids show up before so we thought… there would be a fight.
“We didn’t think it would turn out like this.”
Another resident, who also did not want to be identified, said he had to drive his young daughter home from the park around 5 p.m.
He said, “There are always problems here.”
A large cordon remains around the park and adjacent streets as officers conducted door-to-door investigations in the area.
A forensic team is also on site.
Chief Inspector Kelly Allen of the metropolitan policewho is leading the investigation, said: “My heart goes out to the family of the man who lost his life in this reckless act of violence.
“I believe there were 50-100 people gathered in and around Cheney Row Park playing music at the time of the shooting.
“I urgently need to speak to everyone who was at that event – even if you don’t think you saw anything important, you need to come forward.
“There will be footage and footage shot during the event, and we need to see it.
“Make sure all this material is saved – we will provide a link to upload it soon.
“To anyone considering whether or not to go to the police, I ask you this morning to put yourself in the position of the victim’s grieving mother and father. They deserve answers.”
Witnesses can contact the police on 101, citing reference 267/24jul, or call Crimestoppers anonymously on 0800 555 111.