A police officer will not face prosecution over the death of Rashan Charles.
The 20-year-old died on 22 July after being chased into a shop in Dalston, east London and apprehended by police.
A common assault charge against a Met Police officer was considered by the Crown Prosecution Service (CPS), but it said the “evidential test” had not been met.
The Met Police said it “had nothing to add” to the decision.
The force said Mr Charles was taken ill after trying to swallow an object and was later pronounced dead at the Royal London Hospital.
His death sparked violent clashes in Hackney, with protesters throwing fireworks and bottles at riot police.
The Independent Office for Police Conduct referred a file of evidence to the CPS in relation to one Met Police officer for a possible charge of common assault.
In a statement, the CPS said charges would not be pressed.
“The CPS has considered the matter and decided the evidential test for a prosecution for common assault is not met,” it added.
“We will therefore not be taking any further action regarding this offence.”
Leroy Logan MBE, a retired Metropolitan Police superintendent, criticised the decision not to charge the officer.
He said: “To be quite honest, it is another another slap in the face for families of bereaved families who believe the police are untouchable.
“It is something that needs to change.”
An inquest into Mr Charles’s death is expected to be held in front of a jury on 4 June.
At a pre-inquest review in November, all officers involved in the death were granted anonymity, despite the coroner Mary Hassell rejecting claims there was a “direct threat to officers’ lives”.