The victim of the fatal shooting in Roman Way has been named by police as 22-year-old Imani Allaway-Muir.
Emergency services rushed to the scene at 3.20pm on Saturday afternoon following reports of shots fired.
Police officers and the London Ambulance Service found Mr Allaway-Muir had been shot close to a playground in the Westbourne Estate, Holloway.
Despite their best efforts, he was pronounced dead at the scene.
A post mortem is due to take place later this week.
DCI Neil John, of specialist crime, said: “This was a shocking incident that happened in broad daylight and we believe many people in and around Roman Way would have heard a number of gunshots.
“I would urge anyone that has any information, or video footage, of the area at the time of the incident to contact police.
“The family of a young man have been left devastated by his death and my team of detectives is working relentlessly to identify and arrest those involved.”
A Section 60 Order covering the whole of Islington and Camden was put in place from 2pm on Sunday until 4am today. The order allows police to stop and search anyone without having to have reason for suspicion, as is usually the case.
There have been no arrests.
A spokesperson for Scotland Yard said: “The public have a huge role in helping to both prevent and detect crime. We need to hear from anyone who has information about this crime, or about someone they suspect to be carrying a weapon or involved in organised crime.”
Anyone who witnessed the incident, or who has video or images that could assist police, is asked to call 101 ref CAD 4432/4 July.
To remain anonymous contact the independent charity Crimestoppers on 0800 555 111.
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