A Metropolitan Police officer who was being investigated after the death of Rashan Charles will not be prosecuted.
The 20-year-old died on July 22 last year having earlier been apprehended by police and at least one member of the public after running into a shop in Dalston, east London.
The Crown Prosecution Service (CPS) had been considering a common assault charge against the officer after a referral from the Independent Office for Police Conduct (IOPC), previously known as the Independent Police Complaints Commission (IPCC).
A CPS spokeswoman said: "Following the death of Rashan Charles in July 2017, the Independent Office for Police Conduct referred a file of evidence in relation to one Metropolitan Police? officer for a possible charge of common assault.
"The CPS has considered the matter and decided the evidential test for a prosecution for common assault is not met. We will therefore not be taking any further action regarding this offence."
Mr Charles's death sparked violent street protests in east London, with threats made against police officers.
An initial IPCC investigation last year found that after he was detained, attempts were made to remove an object from Mr Charles's mouth or throat.
It was later revealed that a package extracted from his body contained a mixture of caffeine and paracetamol.
An inquest into Mr Charles's death is expected to be held in front of a jury on June 4.
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".