A teenager was shot near a community hall as scores of people attended a party there.
Detectives are appealing for information and witnesses to come forward after the victim was left fighting for his life after being shot in Tulse Hill.
Police were called at approximately 9.40pm on Sunday, 16 June to reports of shots fired on the Tulse Hill Estate, SW2.
A 17-year-old male subsequently attended hospital with gunshot wounds where he remains in a critical condition. His next of kin have been informed.
A crime scene remains in place.
Investigating officer Detective Inspector Ed Facer said: “The incident occurred in the street near to the Jubilee Hall Community Centre on the estate.
“We believe that there may have been a large number of people in the area at the time as an event was taking place at the community centre around the time of the shooting.
“Were you there? Did you see anything? Of particular interest would be anyone with mobile phone or dash cam footage of the event or surrounding circumstances. We need to hear from you to build on our understanding of what unfolded.”
Police are appealing for witnesses as well as anyone who was at the event at the time.
Detectives from the Serious Crime Trident Command are investigating the shooting and can be contacted on 101 quoting reference CAD7689/16JUN19.
Information can be given anonymously on Crimestoppers via 0800 555 111 or by visiting https://crimestoppers-uk.org/give-information
No arrests have been made; enquiries continue.