Detectives investigating the fatal stabbing of a 26-year-old man are offering a £20,000 reward for video footage of the attack.
Met Police say a crowd of up to 70 people are believed to have been present when Bilal Kargbo was stabbed to death in Peckham Rye, south-east London, on April 28.
Kargbo was killed in broad daylight and police believe witnesses were filming at the time.
According to the force, a 22-year-old man has been charged with murder in connection with the attack.
Meanwhile, a 28-year-old man who was arrested on suspicion of assisting an offender and bailed until a date in early June has since been released with no further action.
Kargo’s family have launched a public appeal for information that could aid the investigation into his murder.
In a statement released via the police, the father-of-three’s family asked people to “think of the trauma and hurt caused to our family”.
“Bilal has left behind three lovely children who deserve justice,” it reads.
“Our family is absolutely devastated with Bilal’s loss; he was a wonderful father, partner, son and friend. Bilal meant so much to us and it is heart-breaking to know that we will never see or speak to him again.
“It is hard to put into words the suffering that this has caused our family and it will take a long time for us to come to terms with what has happened.”
The Met Police believe that a crowd of between 60 and 70 people gathered as Kargbo was stabbed during an “altercation”.
The force is now offering a reward of £20,000 for video footage “that would assist and ultimately lead to the conviction of the person(s) responsible”.
Detective inspector Jason Grafham, who is leading the investigation, said: “Crucial to our investigation, the enquiry team believe a number of people recorded the attack on their mobile devices.”
“I would urge anyone that hasn’t spoken to police to contact our incident room as soon as possible,” he added.
Anyone with information is asked to call police on 020 8785 8267 or Crimestoppers anonymously on 0800 555 111.