Ramane Wiggan was shot dead at the block in March 2019, after he travelled to the area to collect a drugs debt of £10,000.
26 year old Kaine Gilead was convicted of murder at the Old Bailey.
Police were called after a neighbour heard a gunshot at a residential property in Friar Mews.
Officers attended along with London Ambulance Service and found Ramane seriously injured on a balcony walkway.
Despite the efforts of emergency services, who carried out first aid at the scene, Ramane died a short time later.
It was later established that he had been shot from behind by a Glock pistol, with one of the bullets passing through his chest.
A murder investigation was launched and officers carried out urgent enquiries to track down the person responsible.
Analysis of mobile phone data, along with other intelligence, resulted in officers identifying Kaine Gilead as the main suspect.
Gilead took a minicab to Liverpool on the day after the murder, before returning to London on the 24th of April 2019.
He was arrested on the 2nd of May 2019 after officers saw him visiting his mother’s address in the West Norwood area.
He was bailed while officers carried out further enquiries, which included a review of data collected from Gilead’s mobile phones. One of the mobiles was used in the area of the murder shortly before Ramane was shot.
It also showed several calls between Gilead and Ramane in the hour prior to the shooting.
Gilead was further arrested in September 2020 and charged by the Crown Prosecution Service the following day. He made no comment during interviews with officers.
Judge Topolski, sentencing Gilead, said he had committed a “brutal and callous” murder that would “haunt Ramane’s mother, family, friends, for many years”.
Detective Chief Inspector Kate Kieran, who worked on the investigation, said: “The evidence we collected against Gilead was overwhelming and showed him to have played a key part in the deliberate, planned and cold-blooded murder of Ramane.
“This case is also a tragic reminder of the misery drugs cause within communities and demonstrates how they can often act as a catalyst to more serious crimes.”