Obina Ezeoke is accused of killing mother-of-nine Annie Besala Ekofo and Bervil Kalikaka-Ekofo, 21, at a flat in East Finchley.
A 24-year-old man has been charged with two counts of murder after a woman and her nephew were shot dead in north London.
Obina Ezeoke is accused of killing mother-of-nine Annie Besala Ekofo and Bervil Kalikaka-Ekofo at a flat in East Finchley on Thursday morning.
Scotland Yard said Ezeoke is in custody and will appear at Hendon Magistrates Court later.
On Saturday, a post-mortem examination determined that Mr Kalikaka-Ekofo, a 21-year-old psychology student, had died from a gunshot wound to the head.
It is feared their deaths were a case of mistaken identity, with detectives saying there has been no evidence to suggest they were the intended targets of the shooting
Four other people, including a child, were inside the flat in Elmshurst Crescent at the time of the attack but were not harmed.
Mrs Besala has been described as a “wonderful and loving mother” who was the “glue that kept everyone together” in the family, while Mr Kalikaka-Ekofo’s father said his son “never looked for trouble”.
A 20-year-old man arrested on suspicion of murder remains on bail until late October. (Sky News)