One of his last major cases (October 2010) was presiding over the inquest of the barrister Mark Saunders, controversially shot to death by Metropolitan Police on 6 May 2008.
After the ruling of 'lawful killing', Knapman revealed that he would use his powers as coroner to highlight lessons that should be learned by the police for the future[1] and would make copies of his recommendation available to Secretary of State for Justice, Kenneth Clarke.
As the deputy coroner he was much involved with the preparation of the inquest into the death of Sandra Rivett, nanny to the children of Lord Lucan.
He sat with the coroner during the inquest (16–19 November June 1975), when the jury returned the verdict that Lord Lucan should stand trial at The Old Bailey charged with the murder of Sandra Rivett.
Then, it being a Bank holiday weekend, in the full blaze of publicity and live television, soldiers of the Special Air Service (SAS) successfully rescued the hostages on 5 May.
Then subsequently the coroner and jury heard the following evidence regarding each of the deceased: an outline of personal details, including character of each person provided by a relative; evidence of how precisely they were identified; an indication of where precisely they were at the time of the collision, assisted by visual aids; and a brief summary of injuries and the cause of death provided by the pathologist.
Then, having heard the evidence on each of the 35 people, the coroner announced he was adjourning the inquest for a Public Enquiry to be held by Anthony Hidden QC who had been appointed for that purpose by The Secretary of State for Transport under regulations of The Railways Act 1871.
Re-wiring had recently been performed on Clapham Junction A box, and redundant wires had not been cut back and insulated sufficiently causing a false feed.
Having returned to London, although not specifically recalling it, Knapman said that had he been asked by the Metropolitan Police he would certainly have given consent for hands to be removed from the decomposed bodies.
Lord Justice Brown said "no-one should interpret this judgement as a condemnation of Knapman, almost without exception he handled the many difficulties he faced not merely with sensitivity but with an evident sympathy for the bereaved families.
Sir Thomas Bingham, The Master of the Rolls said, "I reach this decision with regret, the coroner reacted to this horrific tragedy with energy and public spirit.
Knapman and Dolman were stood down and a new coroner was appointed by the High Court and Home Office, Dr John Burton.
In February 2000, Deputy Prime Minister John Prescott announced that he had ordered a Public Enquiry into the circumstances surrounding the Marchioness disaster.
The combined speed was 130 mph and ignited fuel, caused a fireball and the first carriage of the Cheltenham train was totally burnt out.
The letter requested the coroner to adjourn the inquest pending the result of a public enquiry conducted by Lord Cullen.
This contrivance was as a consequence of legislation passed only a month earlier, whereby the Lord Chancellor could require an inquest to be adjourned and only resumed if the coroner "believes there is exceptional reason for doing so".
The cause of the crash was found to be the driver of the Thames train from Paddington passing signal SN109 at red, probably due to bad sighting of SN109 and bright sunlight at a low angle, and other factors outlined.
The challenges were: there had been four sites of the bombs; many thousands of "missing persons" reported initially; a cosmopolitan city; disrupted bodies; and computer hard and software of 2005.
Subsequently, Knapman appointed Lady Justice Hallett to be his assistant deputy coroner, and she eventually held inquests into the deaths.
Due to protracted enquiries and legal difficulties, the delayed inquests into both were opened eventually on 6 January 2004 by Michael Burgess, HM Coroner for Surrey and The Royal Household.
Subsequently, he announced he would resign from the cases said to be due to "heavy and constant workload" on 24 July 2006, and he appointed Lady Butler-Sloss as his deputy.
He appointed Lady Butler-Sloss, a retired Court of Appeal judge to hear the inquests as his assistant deputy coroner.
On 7 June 2007, Knapman appointed Lord Justice Scott Baker as his assistant deputy coroner to hear the cases.