Chilling CCTV has been released showing a murder suspect calmly walking away after a father was stabbed to death in a London park
Rocky Djelal was fatally knifed as children played nearby in a "calculated and brazen attack" around lunchtime on Halloween in Southwark Park, south-east London, police said.
Detectives investigating the murder of the 38-year-old have released CCTV footage of the suspect before and after the killing.
Police have said they believe Mr Djelal may have been targeted.
Witnesses described the suspect as a white man aged between 20 and 35 wearing dark clothing underneath a fluorescent hi-vis vest, with a hood covering his face.
It comes as Mr Djelal's family paid tribute to the father-of-one, saying he had a "heart of gold".
They said in a statement: "Thank you to all of the people who rushed to Rocky's aid in the park and made sure our boy was not alone in his final moments.
"We are absolutely grief stricken. We have lost our boy, our son who we adored.
"A father who was idolised by his daughter, a brother who was loved dearly and an uncle, nephew and friend who was loved and respected.
"Anyone who really knew you knows you have a heart of gold and you'd do anything to help those you love."
Mr Djelal was jailed for six years in 2014 after pleading guilty to conspiracy to cause GBH in the mistaken identity murder of City porter Christopher Foster.
The knifeman who murdered Mr Foster in a revenge attack against the wrong man, Aytach Lisani, was jailed for life with a minimum of 23 years at the Old Bailey.
In 2001, Mr Djelal was cleared of taking part in a brutal Christmas Eve attack on a Turkish asylum seeker which left him permanently brain damaged.
Officers appealed for witnesses or anyone with pictures and videos from inside the park on October 31 to get in touch.
Mr Djelal was found fatally injured just before 2pm on Wednesday and died at the scene despite the efforts of medical staff and a team from the London Air Ambulance.
A post-mortem gave the cause of death as a stab wound.
