Detectives are appealing for witnesses and information after a 19-year-old was stabbed to death in south-east London.
The teenager was injured in Jubilee Park, close to Tent Peg Lane in Petts Wood, at about 2.30pm on Wednesday.
An air ambulance was called, but he died at the scene.
His family has been told, but he is yet to be named by police.
A post-mortem examination on Friday gave his cause of death as a stab wound to the heart.
Detective Chief Inspector Laura Semple said: “This investigation continues at pace and we are making progress in piecing together the events that led to this young man losing his life.
“However, we need the help of the public.
“I would ask anyone who was in the park area and who saw the events leading up to this attack to come forward and speak to police.
“I am especially keen to hear from people who may have captured events on camera or taken images that could assist our work.”
She said anyone with relevant footage or images can uploaded them at Public Portal (mipp.police.uk).
Anyone with information is asked to call police via 101 quoting reference CAD 3972/20Sep.
To remain anonymous contact Crimestoppers on 0800 555 111.
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know.