The police watchdog has ruled Scotland Yard inadequately investigated officers for using excessive force against a wheelchair-bound student fees protester, his solicitor said today.
The force also faces criticism for failing to pass on Jody McIntyre's case to the Crown Prosecution Service, Michael Oswald, of Bhatt Murphy law firm, added.
The Independent Police Complaints Commission launched a probe after the Metropolitan Police's Directorate of Professional Standards found officers were justified in pulling him from his wheelchair and "inadvertently" hitting him with a baton at the student fees demonstrations in December.
The IPCC has concluded the failings of previous inquiries "allowed an officer to escape criminal sanctions", the law firm said.
Investigators found the officer accused of dragging Mr McIntyre across the ground has a disciplinary case to answer and the protester has a "legitimate grievance" in being struck with a baton, it was claimed.
Mr McIntyre welcomed the IPCC findings which "confirmed my view that the investigation that was conducted by the Met was seriously deficient".
"The conclusions that have been reached by the IPCC represent a small step towards the accountability that I seek in respect of the way in which I was treated by police officers on December 9 2010," he said in a statement.
"However, there is still some considerable way to go in this regard and it is of particular concern to me that the officer who dragged me across the road has escaped criminal sanction for his actions because of the failings in the investigation that was conducted by the Met."
He said he is considering legal action.
Mr Oswald added: "The conclusions of the IPCC have vindicated the serious concerns held by Mr McIntyre with regard to the quality of the investigation that was conducted by the Metropolitan Police Service into their officers' treatment of him."
Mr McIntyre said he was the victim of unprovoked action after video footage of the incident came to light. He also said the treatment amounted to discrimination on the basis of his disability.