The pal claimed Mr Kaba was unarmed and had a baby on the way.
They added: "He [Chris] was unarmed. He was soon to be a father for the first time. This is awful, we're all in huge shock."
Mr Kaba is understood to be in his 20s and, as part of 67, is best known for their track "Lets Lurk".
The group is widely regarded in the UK drill scene after being nominated for Best Newcomer at the MOBO Awards in 2016,
My London reports.
Police said in a statement that a "suspect" vehicle was stopped following "tactical contact" at 9.51pm on Monday in Kirkstall Gardens, Streatham Hill,
Lambeth,London.
According to a friend who visited the crime scene, Mr Kaba was unarmed and had a baby on the way (
Image:
UkNewsinPictures)
A specialist firearms officer shot a man in his 20s, the statement added, however police have not said why a firearm was used.
The man received first aid from officers at the scene before being taken to hospital.
One local resident who overheard the commotion wrote on social media: "Awful event in Streatham Hill tonight. I and many other neighbours heard two gunshots.
"Have also heard reports from neighbours who say they saw police stop a car and shoot a man.
"They then performed CPR on him before taking him away. Lots of armed police and helicopter."
Mr Kaba received first aid from officers at the scene before being taken to hospital (
Image:
PA)
The Met’s Directorate of Professional Standards and the
Independent Office for Police Conduct have been contacted following the incident.
No other injuries were reported, though cordons and road closures are in place while police carry out their investigation.
One local resident who overheard the commotion wrote on social media: "Awful event in Streatham Hill tonight.
"I and many other neighbours heard two gunshots.
A police officer's firearm was discharged after authorities pursued Mr Kaba's vehicle (
Image:
UkNewsinPictures)
"Have also heard reports from neighbours who say they saw police stop a car and shoot a man. They then performed CPR on him before taking him away. Lots of armed police and helicopter."
A Metropolitan Police spokeswoman said: "At 9.51pm on Monday, September 5, specialist firearms officers were in pursuit of a suspect vehicle in the Lambeth area.
"The vehicle was stopped following tactical contact in Kirkstall Gardens, Streatham Hill. A police firearm was discharged.
"An occupant of the suspect vehicle - a man believed to be aged in his 20s - sustained a gunshot injury.
