London, England (CNN) -- No charges will be filed against a police officer who struck a man who later died during the G-20 protests in London last year, the director of public prosecutions said Thursday.
Ian Tomlinson died April 1, 2009, in London's financial district as demonstrations took place against the G-20 summit being held in the city. He was returning home from his job selling newspapers and had not been taking part in the protests.
Videos shot by witnesses showed a police officer apparently pushing Tomlinson to the ground. Prosecutors said he was also struck by a baton.
An initial autopsy ruled Tomlinson died of a heart attack, but a second one found he died from abdominal hemorrhage.
The Independent Police Complaints Commission investigated Tomlinson's death and passed the findings to the Crown Prosecution Service to decide whether any charges should be filed against the officer.
"After a thorough and careful consideration of all the available evidence, the CPS has decided that there is no realistic prospect of a conviction against (the officer) for any offense arising from the matter investigated and that no charges should be brought against him," Keir Starmer, the director of public prosecutions, announced Thursday.
Tomlinson family lawyer Jules Carey said it was "disgraceful" that no one has been prosecuted over the death and said the family would consider whether to appeal.
"Clearly it is a disgraceful decision," he said, Britain's Press Association reported. "The CPS have accepted the conduct of the officer was unlawful."
Tomlinson's son, Paul King, said the family was stunned by the decision, the PA reported.
Prosecutors said they did find the officer's actions could have been considered an assault, because Tomlinson posed no threat to anyone when he was hit.
They considered a manslaughter charge but said there was no realistic prospect of conviction because of the conflicting autopsy findings. Because the first coroner found Tomlinson died of natural causes, it would be impossible to prove he died because of the blows he suffered, prosecutors said.
Prosecutors also considered assault charges, but said convictions wouldn't have been possible there, either. If the push had caused Tomlinson's death, they said, the appropriate charge would have been manslaughter -- but they already determined they couldn't prove that charge. If the baton blow was to blame, it would have amounted to common assault -- but prosecutors missed a strict six-month time limit for filing charges on that count.
The last possible charge was for misconduct in public office, which is essentially abuse of power. However, simply being a police officer who commits a criminal offense does not amount to misconduct, prosecutors said -- and they could not prove he committed a crime in the first place.
The Crown Prosecution Service left open the possibility there could be charges later. They said they will give their decision to the inquest on Tomlinson's death, and if the inquest reveals any new evidence, prosecutors may reconsider charges.