PC Simon Harwood, cleared of the manslaughter of Ian Tomlinson, had a controversial disciplinary record that could not be put before the jury.
Max Nash, PA Wire
A series of allegations were made against him in a period of 12 years, but details were ruled inadmissible as part of the trial.
The officer faced a number of complaints about his behaviour, one of which prompted a chief to say his conduct had "fallen well below that expected of a police officer".
After the inquest into Mr Tomlinson's death last year, lawyers for the father-of-nine's family claimed Harwood kept his job by "side-stepping" the disciplinary process.
Matthew Ryder QC said the officer had admitted at hitting "red-mist mode" in the past.
The barrister described him as a "rogue officer, who should not have been where he was, in a position to do what he did".
Details of the officer's background were deemed legally inadmissible at both the inquest and the subsequent criminal trial for manslaughter.
Allegations against Harwood included:
APRIL 2000: PC Harwood was accused of involvement in a "road-rage" incident with another motorist while off-duty. Witnesses claimed he shouted, knocked the motorist over his car door and then announced he was a police officer and arrested him for common assault.
Reviewing the evidence, a Metropolitan Police commander decided Harwood's behaviour, which resulted in the driver receiving compensation, was not up to standard, Mr Ryder said.
PC Harwood was told he should face disciplinary proceedings but retired from the force days before proceedings would have begun.
The officer had applied to be "medically retired", citing injuries sustained in an unrelated traffic accident which occurred around three years previously.
Just one weekend later, he began working as a civilian employee for the force, relocating to an office in Croydon, south London. Around 18 months after that, he was back on the streets in uniform.
APRIL 2003: Having joined neighbouring Surrey Police, the force received a complaint from fellow officer about Pc Harwood using excessive force. PC Harwood, while carrying out an arrest at a flat, was allegedly seen grabbing a suspect by the throat and pushing him into a wooden table, causing it to break.
It was claimed he then punched him against a wall, according to the fellow officer.
As he was led away, the man shouted at Harwood: "I'll have you." Harwood allegedly replied: "Go on then, I'll do you all over again."
PC Newman, the officer who filed the complaint, said Harwood "went over the top" and that he was "shocked". But the complaint was logged as unsubstantiated. A month later, Harwood applied to be transferred back to the Met.
FEBRUARY 2005: Concerns over his behaviour continued after he joined the Met's specialist territorial support group. A complaint was made by a member of the public who said he saw Harwood kneeing a man in the back during an arrest on Streatham High Street. The complaint was not upheld.
2006: In another complaint the following year, Harwood was accused of attempting to steal a mobile phone and threatening violence. The complaint was resolved locally with no further action taken.
2008: Harwood stopped AA man Junior Samms, who later alleged that while he was handcuffed Harwood had twisted the cuffs and shouted at him.
In another incident that year, the only complaint against Harwood that was upheld, he was accused of unlawfully accessing of the police national computer (PNC).
Harwood accessed the PNC database after discovering his wife had been involved in a road traffic collision.Questioned about unlawful accessing of the PNC, Harwood admitted he ignored a colleague, who warned him not to look up details of the accident on the database.
He told investigators he went into "red-mist mode" after discovering his wife had been involved in the accident, Mr Ryder said.
Details of Harwood's personnel record were deemed inadmissible at both the inquest into his death and the manslaughter trial.
The coroner decided that it was not appropriate for the jury to hear this evidence because only one incident was proved.
In the criminal proceedings, Mr Justice Fulford ruled that the trial would become too complicated if details of the allegations were allowed in.
This was because, being unproven, prosecutors would have had to call evidence and witnesses linked to the allegations that they wished to include.