A General Medical Council disciplinary panel previously ruled that Dr Freddy Patel acted in a way that amounted to misconduct in two earlier post-mortem examinations, meaning his fitness to practise was impaired.
The panel also ruled that Dr Patel had displayed deficient professional performance in a third post-mortem.
He has already been suspended from the Home Office register of forensic pathologists after questions were asked about the autopsy carried out on the body of 47-year-old Mr Tomlinson, who died in April last year after being struck by police.
A possible prosecution of the officers was dropped by the Crown Prosecution Service when Dr Patel's evidence conflicted with that of two other pathologists.
The panel had already concluded that Dr Patel was "irresponsible" and failed to meet professional standards during his examinations of the bodies of a five-year-old girl in 2002, a four-week-old baby in 2003 and a woman who died in 2005.
Dr Patel, 63, behaved irresponsibly, failed to meet standards expected of a Home Office pathologist and acted in a way liable to bring the profession into disrepute when he changed the woman's cause of death in 2005, the panel found.
He carried out a post-mortem examination on January 5 2005, and decided she had died due to a blood clot in the coronary arteries. A month later, following a second post-mortem by another pathologist, he changed the cause of death to a brain haemorrhage in line with the new findings.
In the GMC ruling, Mr Davies said Dr Patel's "acts and omissions were very serious" and amounted to misconduct.
He said pathologists "must not set aside their professional judgment for any of the parties involved during or after a post-mortem examination for reasons of expediency or anything else".
Dr Patel was also found to be guilty of misconduct in a post-mortem examination on the four-week-old baby in August 2003.
Richard Davies, chairman of the GMC panel, said suspension was necessary as Dr Patel's shortcomings had been "very serious".
He said: "The panel considers it to be most important that the public be assured that the independence of professional forensic pathologists can be relied upon and that neither those working in the specialty, nor anyone else, should gain the impression that the misleading conduct for which you have been criticised will be treated other than with substantial seriousness.
"For these reasons, the panel has determined that a period of suspension in your registration is appropriate in your case."
Dr Patel will face a fitness to practise panel after his suspension. He will be expected to improve his knowledge of the law and find pathologists to review his work. He will also be barred from post-mortem examinations on adults in non-suspicious circumstances and have to stop working as an expert witness for the defence.
Mr Davies added that Dr Patel had not addressed his failings.