A 27-year-old man was arrested on suspicion of murder on the evening of Thursday, 21 October.
A second man was arrested on suspicion of assisting an offender. They have both been take to a police station where they remain in custody.
At approximately 6.25am on Thursday, 21 October, police were alerted by staff at a south London hospital after a man in his 20s was admitted suffering gunshot injuries.
Despite the efforts of emergency services, he died later this afternoon. His next of kin have been informed; formal identification is yet to take place.
A post-mortem examination will be held in due course.
Detectives from the Specialist Crime Command are investigating.
An incident room has opened under Detective Chief Inspector Mark Rogers.
It is believed that the man sustained his injuries following a shooting in the vicinity of Belinda Road, SW9 shortly after 6am. A crime scene remains in place.
DCI Mark Rogers, said: “Our thoughts remain with the man’s family, who are being supported by specialist officers.
“I would urge any witnesses, or anyone who saw or heard anything suspicious in the area of Belinda Road to please come forward and speak with us. Any piece of information could be vital in helping us to identify those responsible for taking a young man’s life.”
Additional officers will be patrolling in and around the area and anyone with concerns is asked to speak to them.
Anyone with information is asked to contact the incident room on 020 8345 3715 or via 101 quoting CAD 1151/21Oct.
You can also provide information to the independent charity Crimestoppers on 0800 555 111.