Police have named the man killed in a shooting branded "horrific" by police in the early hours of Sunday morning.
Dean Edwards was shot in the back of the head as he walled through Betts Park in Penge, south London.
Police were called by the London Ambulance Service to a man collapsed on Croydon Road at around 2.20am.
The Metropolitan Police said in a statement that they were confident the victim is the 43-year-old from of South Norwood, though a post-mortem exam has yet to take place.
Mr Edward's family have been informed.
Detectives say Mr Edwards was walking through the park and was about to leave via the Croydon Road exit near the Tremaine Road junction,when he was shot.
Detective Chief Inspector Kate Kieran said a "fast-paced investigation" was examining the "horrific incident".
She said: "We are keen to speak to anyone who was in or around Betts Park in Penge on the late evening of Saturday or early into Sunday.
"We are particularly interested in anyone that might have seen or heard anything suspicious between 12.15am and 1am on Sunday, or any time before or after this.
"Anyone who lives in the area, or who was there at that time, may well have information that could assist us tremendously. No matter how insignificant it may seem, we urge you to please get in touch."
Those with information are asked to contact homicide detective via the incident room on 0208 721 4868, or by dialling 101 and quoting CAD 1402/12JUL.
Information can also be provided anonymously via independent charity Crimestoppers on 0800 555 111.
