A Scotland Yard officer id to appear in court accused of killing Ian Tomlinson at the G20 protests.
Mr Tomlinson, a homeless 47-year-old newspaper seller, collapsed and died on the fringes of the demonstrations in central London on April 1 2009.
Pc Simon Harwood, a father of two from Carshalton, Surrey, will appear before a judge at Southwark Crown Court charged with manslaughter.
The Director of Public Prosecutions charged Harwood, 44, over the death after reviewing an inquest jury's unlawful killing verdict.
Keir Starmer QC said new medical evidence at the inquest and the opinions of experts during the hearing helped change his mind.
The death became an international controversy after New York businessman Christopher La Jaunie handed footage he had taken of a police confrontation to the Guardian newspaper.
CCTV images, police helicopter footage and hand-held video recordings show Mr Tomlinson cutting a lonely figure as he staggered away from a police cordon after being hit with a baton.
Footage then shows Mr Tomlinson gesturing to police and appearing angry after being sent tumbling to the ground.
His widow Julia said the death devastated her family, adding: "I remember feeling he was the best thing that ever happened to me."
Harwood - who is on unconditional bail - is expected to enter a plea during the court hearing. Lawyers have said he could face a trial at the Old Bailey in the new year.