No: 2002/1875/C3 
Neutral Citation Number: [2003] EWCA Crim 3870
IN THE COURT OF APPEAL 
CRIMINAL DIVISION 
Royal Courts of Justice
Strand
London, WC2 

Thursday, 18 December 2003
 
B E F O R E:

LORD JUSTICE BUXTON 

MR JUSTICE GOLDRING 
 
MR JUSTICE MACKAY 

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R E G I N A 

-v- 

PETER SHARP
 
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MR R TRAVERS AND MR P SINCLAIR appeared on behalf of the APPELLANT
MR W CLEGG QC AND MR J CAUDLE appeared on behalf of the CROWN
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J U D G M E N T
1.	LORD JUSTICE BUXTON:  This is an appeal brought on a reference by the Criminal Cases Review Commission from the conviction of Mr Peter Sharp, now aged 70, on one count of murder, in the Crown Court at Maidstone on 23rd November 1992 in respect of which he was sentenced to life imprisonment.  
2.	The case that Mr Sharp faced at that trial was that he had shot two victims, a Mr Leslie Taylor and his wife, Mrs Joy Taylor.  Mr Taylor survived that incident.  Mrs Taylor unfortunately died.  
3.	The appellant and Mrs Taylor had lived together for a number of years before Mrs Taylor (as she became) left Mr Sharp in 1990 and went to live with Mr Leslie Taylor whom she married in January 1991.  It was the prosecution case that the appellant was obsessed with recovering the affections of Mrs Taylor.  He had, it was alleged, hired someone to observe the family's movements and he had harassed the couple both at home and at work.  He had threatened to kill her.  She indeed had gone so far as to obtain a non-molestation order against him in October 1990.  
4.	The offence occurred just after midnight on 25th November 1991.  The couple drove up to their home in their car, followed by the appellant who stopped his car behind theirs.  Mr Taylor got out of the car.  The appellant shot him in the head causing him to lose consciousness.  He then walked to the driver's door of the car and shot Mrs Taylor as she sat in the driver's seat.  He telephoned Mrs Taylor's father, saying: "They are both dead.  I have shot them".  He was arrested later that day a couple of miles from the crime scene. The gun that he used was never found.  
5.	At the trial the appellant relied on a detailed and circumstantial defence in support of which he gave evidence.  We need to set that out in some detail because that fact has an important bearing on the issues in this appeal.  
6.	Mr Sharp's case was that on the afternoon of the 24th November he had received a phone call from someone whom he thought to be Mrs Taylor, speaking incoherently.  Out of concern for what he thought might be her condition he went to the home of the Taylors on a couple of occasions, and when he saw they were not there on the second occasion he waited for them to return.  When they did eventually come back he pulled up behind them, intending to inquire whether Mrs Taylor was in fact well or not.  He claimed that as he got out of the car he saw Mr Taylor get out of his vehicle, Mr Taylor making threatening and derogatory remarks to him.  He saw Mr Taylor pull something out of his car which the appellant thought to be an iron bar.  The appellant went over to him and when he tried to grab the bar he realised that it was in fact a gun.  As they struggled he heard a loud bang.  The next thing he remembered was being in a police station.  The death of Mrs Taylor with which he was accused was therefore an accident.  It should be said that Mr Sharp was also charged with and convicted of attempted murder in the case of Mr Taylor and possessing a firearm with intent to endanger life.  No appeal is brought in respect of those matters. 
7.	It will be clear from the account that we have given that the defence of accident in relation to Mrs Taylor was extremely difficult, and it was no doubt no surprise that it was rejected by the jury.  That it would be so rejected was also the view of Mr Sharp's then advisers, as we shall in due course see.  
8.	An application for permission to appeal was made to this court, complaining of various alleged failings on the part of counsel and solicitors.  Statements were taken from those then concerned.  The single judge said that there was no basis for the court to interfere.  The appeal was not further pursued.  
9.	The matter returns to this court, as we have said, through a reference by the Criminal Cases Review Commission.  They had received submissions from Mr Sharp and his solicitors in March 1998, in particular in relation to information about and the effects of a drug called Halcion.  The three grounds upon which submissions were made to the Commission were first that the defence lawyers had failed to adduce evidence of the long-term effect of Halcion on Mr Sharp; secondly that they did not properly prepare for Mr Sharp's trial; and thirdly that the police failed to disclose a tape recording by the victim's daughter which did not accord with her evidence.  The Commission rejected all of those three arguments and they are not pursued in front of us.  However, the first of them has some impact upon the ground that is argued before us, because the Commission, apparently on its own motion, decided that there was, as they put it, an additional issue not raised in Mr Sharp's application: that is to say, whether a defence of diminished responsibility had been available to him at the trial and should now be considered by this court.  
10.	The Commission's view that a defence of diminished responsibility may have been available and should in any event be considered by the court is strongly related to the drug Halcion and the evidence of its effects.  Halcion is a drug that was used to treat sleeping disorders.  For the purpose of the present appeal we accept that it was being taken by the appellant in substantial amounts.  The exact amounts are a matter of some controversy but we do not think that affects the issues in the appeal.  And we also accept, as we shall explain in more detail, that the drug is said by at least some psychiatrists to cause behavioural disorders, some of them of the most serious nature.  
11.	We have had some difficulty in elucidating what were Mr Sharp's instructions to his lawyers leading up to his trial.  It is clear that at some stages he claimed amnesia as to the events that occurred.  He was examined by Dr Burman in order to report to the court in May 1992.  That, it will be recalled, was some six months after the incident and after his arrest.  Dr Burman, who is a member of the Royal College of Psychiatrists and had then for nearly 15 years been a consultant psychiatrist, was asked to examine Mr Sharp by reference from the medical officer of the prison where he was then held.  Mr Sharp effectively told Dr Burman that he could not recall what had occurred; he was suffering from amnesia.  Dr Burman set out in some learned detail the psychiatric views of the effect and presence of amnesia in cases of traumatic stress, and then he said this at page 5 of his report:
"In Mr Sharp's case I consider that he adopted, in a voluntary fashion, a disinclination to recall information during the police interviews but that it is quite possible that he has subsequently convinced himself that he has actually lost his memory.  From a common sense position and a simpler one my preferred conclusion is that this is probably a pretence and that Mr Sharp is malingering."
Dr Burman then went on to address the issue of Halcion.  There is no indication of how that directly came to his attention, save that it appears that from page 2 of the report that Mr Sharp had as part of the history told Dr Burman of the taking of Halcion.  Dr Burman gave an account of what Mr Sharp had said.  He then said this in relation to Halcion in the last paragraph of his report:
"There have been some rare reports of extreme mood and behavioural disturbances on individuals receiving the above sleeping medication including violence.  The drug has been withdrawn (taken off the market) in view of adverse side effects.  From his account Mr Sharp did not complain of any daytime adverse reactions or side effects whilst receiving this drug such as mood changes, irritability and other effects appertaining to Benzodiazapene usage.  On ceasing the drug likewise his only complaint has been of insomnia and frequent non-specific dreaming episodes at night.  It is therefore not apparent to me that Halcion has any bearing on Mr Sharp's case.  I should point out however that the clinical opinion of whether, to the contrary, Halcion may have had an adverse effect on Mr Sharp's mental state by way of mitigation is too specialised an opinion for me to offer.  That is to say that I am not an expert on the adverse effects of this drug."  
We do not know, and the Commission did not appear to inquire into, the state of the proceedings in May 1992 when Dr Burman wrote his report, nor into the case advanced on behalf of Mr Sharp at what appears to have been a three day committal proceedings in the Magistrates Court.  We know about these proceedings only from a document that happens to be in our papers, in circumstances again that we are not clear about, and which was also before the Commission.  This is described as a Note on Taxation, signed by the junior member of the Bar who represented Mr Sharp at the trial.  No statement has been taken from that gentlemen:  we are told that he has retired from the Bar and is now working for the United Nations.  Nonetheless, we have no hesitation in saying that we should take this statement at its face value.  It was a considered account given by the member of the Bar who had been responsible for the case throughout, in response to the enquiries of the taxation authorities.  It was an account to support the claim that counsel was making.  In the absence of any counter indication, of which there is none, this court is bound to accept that it is a full and accurate account so far as it goes.  It is therefore appropriate to set out some parts of it.  Counsel says this:  
"1. I first met Peter Sharp in the Magistrates' Court when I was instructed to conduct the live committal proceedings.  He was then, as he remains still, a very withdrawn personality.  There was a measure of difficulty in establishing any rapport at the lower court but, nevertheless I managed to substantially cut down the evidence that he required to be given live and so interminably long proceedings were happily reduced to some three days.  
2. I was then instructed as junior counsel.  I have had considerable time to prepare these papers and have made use of that time.  However, on obtaining a proof of evidence from the defendant, it appeared his defence was not to be along the lines hitherto thought.  His defence transferred to the one wholly untenable in view of the surrounding evidence."
He then gives some account of that defence contained in the proof of evidence, which appears to have been in substantially the same terms (paragraph 5 of counsel's note) as the evidence that Mr Sharp gave in detail at the trial.  Counsel then says this in paragraph 6:  
"It was anticipated that the defence run would be a 'Halcion' defence, because the defendant had been on that drug for some 12 years prior to this incident taking place.  The drug is notorious as having character personality disordering effects.  Much work was done on this area..."
We draw from that that the defence originally expected by Mr Sharp's advisers was indeed what was called a Halcion defence, that is to say a claim that the drug had had the character personality disordering effects on Mr Sharp that junior counsel says he was well aware of.  It would appear to be the case, though we cannot be certain of this, that that was a matter ventilated in the three day committal to which counsel refers, and about which we know virtually nothing else.  However, when Mr Sharp settled his proof that defence was apparently abandoned by him.  Its place was taken by the account that he gave at the trial.  
12.	It is unsatisfactory that it has not been possible to discover in detail what actually happened in the preparation of the defence.  Mr Sharp cannot help because we are told from the Bar that he now has complete amnesia in respect of the preparation of the case, and has made a witness statement, to which we will refer later, to that effect.  However, we consider that we are fully entitled on the evidence before us to draw the conclusion that we have already set out.  We are reinforced in that by an extract quoted by the Commission from a letter that Messrs Goldkorns -- that is to say the solicitors who advised Mr Sharp at the trial -- sent to the central taxation unit in June 1993.  We have not seen that letter.  We assume that the Commission did see it.  Having addressed the medical position as shown in Mr Stapleton's Note on Taxation, the solicitors then said this:  
"These matters were put plainly to the defendant who despite having been advised in conference with Queen's Counsel, junior counsel and senior solicitor maintained his plea of not guilty to the end."  
13.	It is however contended before us in this appeal that there was no basis that could properly be used at the trial to put forward what is called the 'Halcion' defence, and that it must be inferred that a decision was taken to abandon the defence, not because Mr Sharp was pleading accident, but because the basis for it was not available.  It will be seen that that contention is extremely difficult in the light of what is said by junior counsel who had conduct of the case.  This submission relies to a substantial extent upon an expert's report that was obtained on 9th November 1992 -- that is to say some eight days before the trial -- from a Dr Scannell who is now unfortunately deceased but who was then a consultant psychiatrist at St. Bartholomew's Hospital.  He gave a detailed account of the circumstances.  He said on page 2 of his report on instructions from Mr Sharp:
"The defendant concurs that he was in the vicinity of the accident at the material time and that it was 'possible' that he was responsible for the shootings, but as he has no firm recollection he is pleading not guilty."   
Those instructions, it will be noted, were given no more than 10 days before Mr Sharp went into the witness box and gave a very circumstantial account of what had occurred.  It is not clear whether Dr Scannell had seen -- indeed it appears from his list of documents that he had not seen -- the proof of evidence made by Mr Sharp, apparently well before this date, to which junior counsel refers in his note.  Having examined Mr Sharp, Dr Scannell says this on page 10 of his report:
"The defendant's presentation at interview is compatible with a life long history of psychopathic disorder.  This presented during his childhood and early teenage years and has been characterised by a criminal behaviour of one variety or another virtually ever since.  Beneath his somewhat defensive manner is a very insecure individual, who on his own admission was very close to his own mother and whose relationships with women subsequently have replicated to an extent his dependency problems on her.
As stated at the outset of this report, the defendant gave a somewhat ambiguous account of the material time, stating that he was probably in the vicinity of the alleged shooting and then later in the interview stating that he was certainly there and admitting later still that he 'possibly' committed the shootings.  However, he then stated that as he had no formal recall of the events in more detail, he is pleading not guilty.  
If he were to plead guilty then the question of whether or not at the material time the defendant was suffering from an abnormality of mind could be raised and the relevance of his psychopathic disorder, reactively depressed state and obsessional behaviour could then be discussed.  Nevertheless the defendant is pleading not guilty, so I can add little at the current time."  
On the basis of that, it is submitted that we should infer that the particular defence now sought to be adduced, that is to say the specific effect of Halcion upon Mr Sharp's behaviour, possibly overlaid by the psychopathic disorder referred to by Dr Scannell, was foreclosed by the fact that Dr Scannell did not avert to the particular issue of Halcion.  It is to be assumed, therefore, it is said, that Mr Sharp and those advising him were deterred from putting forward a defence based on Halcion, or decided that that was not possible to promote that defence.  
14.	We are not prepared to make any such assumption.  It is inconsistent with the Note on Taxation that we have already referred to.  In practical terms it is inconsistent with the account of the development of the defence that we find in that Note.  It is also inconsistent with Mr Sharp's claim that he now makes that he put his evidence forward at the trial as an invention because he could not recall anything about the incident.  We do not accept that that claim is plausible in the light of the history of the case already set out.  
15.	Mr Sharp has sought to support these points with a witness statement which we were asked to receive as fresh evidence.  In paragraph 8 he said this:
"In the long years that I took Halcion I was never aware that I should not take them constantly, nor that doing so could cause serious side effects.  If my Doctor mentioned it when first prescribing me the drug I do not recall such a warning.  Some months after my arrest, when I started to appreciate that  drug had been banned and had been the subject of some publicity, I became somewhat concerned that it might have adversely affected my health.  I was certainly never conscious of any side-effects (except withdrawal symptoms) and I did not personally start to investigate whether the killing or my amnesia might be associated with my use of Halcion until well after the trial.  However, during the months leading up to my trial, I had been told that my solicitors were looking into this issue."  
16.	Mr Sharp's claim that he had no practical interest in Halcion is difficult to maintain in the light of other evidence put before this court, exhibited by a DSI Henneker in a witness statement dated 20th February 2003.  That demonstrates that when Mr Sharp was arrested and searched at the police station on 25th November 1991 there was in his possession a cutting or photocopy from the Daily Mirror dated 3rd October 1991, that is to say some several weeks before these incidents occurred, setting out in detail the alleged dangerous effects, including homicidal effects, that could accrue from Halcion.  Express and detailed complaint was made of the Government's failure to act and various cases were cited.  
17.	Mr Sharp seeks to explain his possession of those documents by saying that his doctor had told him that he would not prescribe any more tablets for the reason that they were about to be withdrawn, and that that happened shortly before the killing.  Mr Sharp continued:
"I was unable to find anyone who had any.  Someone explained that the reason for this was that Halcion had been banned and he gave me a newspaper or cuttings in order to prove to me that he was telling the truth.  However, at that time, I was not particularly interested and did not pay much attention.  My principal concern was to obtain a supply of Halcion."
We do not think that that explanation is capable of belief.  We are reinforced in that assumption by further documents that are exhibited by Superintendent Henneker, that is to say correspondence between Mr Sharp and the Medway Justice's clerk in which Mr Sharp sought the recovery from the Medway Justice's clerk of that correspondence.  It is important to note that the correspondence was directed to the court itself.  He said this in a letter received by the Justice's clerk on 13th January 1992:  
"DI Henneker took some newspaper cuttings from my property when I was arrested.  They concerned my health.  I am writing for them back, or copies.  If not it means me subpoenaing the police to court to say he took them." 
That is plainly inconsistent with a claim that this was all a matter of no importance to him.  The fact that the correspondence was with the Magistrates Court would also appear to us to reinforce the view that we had already formed that this correspondence did or may have played a part in the three day old-style committal proceedings to which counsel referred in his note.  
18.	We have therefore come to the clear conclusion that, firstly, in the passage that we have quoted from his report, Dr Scannell opened up the possibility of a defence of diminished responsibility even though he did not specifically refer to Halcion; secondly, that Halcion was actively under consideration by those advising Mr Sharp, as demonstrated by the report of Dr Burman which they would have read, and in very clear terms by the Note on Taxation; and thirdly by the striking fact that Mr Sharp had this document about Halcion in his possession when he was arrested for this crime.  We are quite satisfied that it was Mr Sharp who insisted on there being a plea of not guilty, as is demonstrated by the instructions that he gave to his solicitors.  We do not accept, and it is wholly unrealistic to think, that the position was as put to us in argument, that he remained in a state of amnesia remembering nothing or nothing reliable up to and after the time that he was interviewed by Mr Scannell, and it was only effectively on the day before the trial that the detailed account that he gave at the trial became available.  
19.	In support of this appeal it is however sought to adduce certain new evidence.  We have already dealt with the statement of Mr Sharp.  As we have said, in so far as it deals with amounts of drugs we do not think that it is of material assistance.  In the respects where it might touch upon the appeal and which we have dealt with in this judgment so far we do not think it is capable of belief, and we are not prepared to listen to it.  
20.	The new evidence, however, apart from that, is of a medical nature.  Mr Sharp submitted to the Criminal Cases Review Commission a report by a Professor van der Kroef, who is a Dutch psychiatrist who has taken a very close interest in Halcion over the years.  Although he had not examined the appellant nor had been involved in the case at any earlier stage, he effectively attributed all of Mr Sharp's criminal behaviour to Halcion.  
21.	The Criminal Cases Review Commission did not think that that gave a complete answer or account but it did instruct another distinguished scientist, Dr Sugarman, to produce a report on its behalf.  Dr Sugarman is a member of the Royal College of Psychiatrists and a consultant forensic psychiatrist who directs the Trevor Gibbens Unit in Maidstone.  The Criminal Cases Review Commission thought that the relevant and important passages in Dr Sugarman's report were as follows, as set out in paragraph 10.9 of their determination:
"In relation to the issue of mens rea, a combination of a disorder of personality, a clear depressive illness, and Halcion withdrawal would be likely to produce an abnormal state of mind...  I cannot see any ground for a defence of insanity.  
A defence of diminished responsibility under section 2 of the Homicide Act 1957 must however be considered.  In my opinion there was an abnormality of mind at the time.  This was caused by disease, namely depression; injury, being the short and long term effects of drugs and alcohol; and an inherent cause, personality disorder.  These combined causes led to impairment of judgment and self control.  If asked in court I would give the opinion that this state would impair an individual's mental responsibility for their actions to some degree at least.  It is a matter for the court to decide whether the degree of impairment could be regarded as 'substantial', as is required for the defence to be accepted.  
Peter Sharp committed a murder and attempted murder at the end part of an escalating series of difficulties, the final compounding factor in all likelihood being withdrawn from the drug Halcion.  There is a reasonable argument that the various difficulties under which he was labouring would have induced an abnormality of mind sufficient for a defence of diminished responsibility."
22.	This led the Commission to conclude as follows, in paragraph 10.14 of their report:  
"In the Commission's view, there is evidence not previously adduced that Mr Sharp was at the time he killed Mrs Taylor, suffering from an abnormality of mind occasioned by depression, long standing personality disorder, drug and alcohol abuse and Halcion withdrawal.  Associating this abnormality of mind together with the factual evidence about the breakdown of his relationship with Mrs Taylor and his obsessive and jealous conduct thereafter, the Commission also considers that there is evidence on which the Court of Appeal could properly conclude that Mr Sharp's responsibility for his actions may have been substantially impaired.  This new evidence is provided primarily by Dr Sugarman, but the Commission also gives significance to Dr Scannell's evidence, albeit recognising that, as Dr Scannell is dead, his evidence is available only in written form."  
23.	On behalf of the appellant further evidence has been adduced from Professor Oswald, who is a follow of the Royal College of Psychiatrists and Emeritus Professor of Psychiatry at the University of Edinburgh.  His opinion, which we think we can put shortly, is summarised in a passage relied on in paragraph 11 of the skeleton argument of the appellant:
"In my opinion there is a substantial probability that those large doses of [Halcion] caused or contributed to cause Mr Sharp to suffer at the time of his offence from an abnormality of mind that would have substantially impaired his responsibility for his actions. Dr Sugarman has come to the same final conclusion, attributing a 'significant role for Halcion'... In my opinion the role was highly significant."  
That therefore is an opinion that placed the abnormality of mind more firmly on Halcion alone rather than on Halcion impacting upon underlying psychopathic or other such tendencies.  
24.	That is not the only evidence before us because the prosecution would seek to adduce the evidence of Dr Joseph who has examined the case on their behalf, and has also had the benefit of examining Mr Sharp himself.  Dr Joseph is also a Fellow of the Royal College of Psychiatrists and a consultant forensic psychiatrist.  We need to set out his conclusions in some detail because they are of importance.  We should say by way of introduction that by scrutiny of the doctor's records Dr Joseph expressed some doubt as to whether the amount of Halcion available to and taken by Mr Sharp was as great as he had claimed.  It is in order to refute that suspicion that part of Mr Sharp's witness statement was put forward.  As we have said, we do not think that this is a live issue because it is quite clear that Dr Joseph rests his conclusions on matters other than the detailed amount of Halcion taken by Mr Sharp.  Dr Joseph says this in paragraph 1 and following of his conclusions:
"Although I have not taken a detailed background history from Mr Sharp myself, I have read the comprehensive psychiatric report of Dr Scannell, and I agree with him that the defendant can be diagnosed as suffering from a psychopathic or anti-social personality disorder.  A central feature of this disorder is an inability to take responsibility for one's behaviour and to offer plausible explanations to attempt to rationalise the anti-social behaviour and present the individual in a good light.  On the basis of my interview with Mr Sharp, this feature is evident in the way he describes his previous relationship with Joy Taylor.  For example, he denies previous violence towards her and denies any memory of making threats to her prior to her death.  Mr Sharp's psychopathic personality disorder can be classified as an abnormality of mind arising from inherent cause, within the terms of section 2 of the Homicide Act 1957.  
2.  I also agree with Dr Scannell that Mr Sharp may have experienced some depressive symptoms in the months prior to the killing as evidenced by low mood, tearfulness and loss of weight. His depressive symptoms will have been precipitated by the end of his relationship with Joy Taylor, but his subsequent behaviour towards her which consisted of stalking, harassment and intimidation, are more likely to have been related to his abnormal personality rather than a depressive illness.  Although Mr Sharp may have been experiencing some symptoms of depression at the material time, I note that he was able to socialise with his friends in the pub or clubs every evening, and was able to form a sexual relationship with another woman in the months prior to the killing.  I do not believe that any symptoms of depression were of sufficient severity to amount to an abnormality of mind within the terms of section 2 of the Homicide Act 1957. 
...  
5. In his report dated 21st May 1992, Dr Burman specifically asked Mr Sharp whether he had experienced any mood changes or abnormal mental or behavioural effects whilst taking Halcion, and he also asked him about withdrawal effects, bearing in mind that Mr Sharp had told him that he had run out of his regular prescription of Halcion two days before he was arrested.  Mr Sharp denied suffering any untoward effects at all whilst he was taking Halcion, and after stopping did not experience withdrawal effects during the day but his insomnia continued with frequent waking throughout the night with brief dreams.  Furthermore, Mr Sharp told Dr Scannell about his 12 to 14 year dependency on Halcion, but there is no mention of any adverse effects.  It is clear, in my opinion, from the report of Dr Burman in particular, that Mr Sharp's intake of Halcion is of no relevance to the killing.  
6.  Although Mr Sharp told Dr Burman that he could remember when he last took his Halcion and could remember seeing Joy Taylor the day before the killing, he now states to me that he has no memory of these events and no memory of any events for days prior to and including the killing.  He claims to have no memory of running a defence at trial that he could remember struggling with Leslie Taylor and the gun going off by accident.  Dr Burman concluded that Mr Sharp was malingering when he claimed to have no memory of the killing, and I concur with that view.  Whether or not Mr Sharp can be considered to be a pathological liar, it is clear that he has changed his story regarding the events surrounding the killing, and I have to conclude that he is a most unreliable informant.  This would be consistent with his psychopathic personality disorder.  
In conclusion, I believe that Mr Sharp's personality disorder can be classified as an abnormality of mind within the terms of section 2 of the Homicide Act 1957.  It is likely that he was suffering from this abnormality of mind at the time of the killing of Joy Taylor.  He was not in my opinion suffering from any other abnormality of mind.  Mr Sharp has not given sufficient details of the killing to enable any opinion to be formed as to whether his abnormality of mind substantially impaired his mental responsibility at the time of the killing.  In my opinion, it is highly unlikely that a jury would have returned a verdict of manslaughter on the grounds of diminished responsibility if the abnormality of mind advanced had been psychopathic personality disorder and the facts of the case had been as set out in the prosecution summary.  Mr Sharp was seen by two experienced psychiatrists prior to his trial who were both aware of his use of Halcion and Dr Burman in particular asked him about the effects of those tablets.  Mr Sharp now appears to be claiming an adverse reaction to those tablets which he did not describe prior to his trial."  
For the avoidance of doubt, we should say that we have reached the conclusions that we set out earlier in this judgment as to inability to rely upon Mr Sharp's testimony from the matters that we referred to at that part in the judgment, and have not relied on the opinion to the same effect expressed by Dr Joseph in paragraph 6 of that report.  
25.	In considering whether in the court should address those matters and should allow the defence of diminished responsibility to be adduced now, when it was not adduced at the trial, there are two conflicting principles that we have to have in mind.  The first is that facts establishing innocence should not be excluded because of a previous mistaken decision by the appellant or by his advisers.  We were referred to authority on that point, the unreported case of Richardson which we have not further had before us, and secondly and more importantly the case of R v Arnold 31 BMLR 24, where Hobhouse LJ said, as quoted by the Commission:
"It is not fatal to an appellant's application that the court receive new evidence that the issue to which it is relevant was not raised at the trial; however, it remains a factor to be taken into consideration.  Ultimately, the most important consideration must always be whether the proffered evidence may afford a ground for allowing the appeal.  If it does not, it is unlikely to be necessary or expedient in the interests of justice that the evidence should be received.  The evidence must provide a basis for a conclusion that the conviction of the appellant was unsafe."  
The second principle however is that it is not open to appellants to choose not to run a defence at trial and then to go back on that decision at the appeal.  That was very clearly stated by the then Lord Chief Justice, Lord Bingham, in R v Campbell [1997] 1 Cr.App.R 492, where Lord Bingham said this:  
"This Court has repeatedly underlined the necessity for defendants in criminal trials to advance their full defence before the jury and call any necessary evidence at that stage.  It is not permissible to advance one defence before the jury and when that has failed, to devise a new defence, perhaps many years later, and then to seek to raise the defence on appeal."  
26.	Here it is necessary therefore, in the light of Lord Bingham's guidance, to investigate why the defence of diminished responsibility was not run.  We have made it clear that we conclude from all the material that it was not run because Mr Sharp had chosen to run a defence of accident in its place, that being inconsistent with the defence now adduced.  The Commission said of that problem, immediately after they quoted Lord Bingham, at paragraph 10.15 of their Determination:
"As stated above the Commission has not approached Mr Sharp to provide an account of why he insisted on running the defence of accident.  It was concluded that there would be no benefit in undertaking such a task as whatever reply he gave this would do little to assist his case.  None of the reports have indicated that Mr Sharp's condition was such as to cause him to be a pathological liar."  
We have to say that we are surprised to read that part of the Commission's findings.  The Commission may wish to consider whether the view expressed there does in fact reflect its policy.  As we understand it, it is not a reason for withholding from enquiry that the outcome of that enquiry may not be of benefit to the appellant.  In this case it was plainly required in the light of the guidance given by Lord Bingham that there should be, in so far as it was possible and in so far as we have attempted to do in this court, a clear understanding of what happened at the trial, and why this defence was not adduced.  Had those matters been pursued, we have to say that we think that this case may well have appeared to the Commission in a different light from that which they thought it to present.  
27.	Secondly, and applying those conflicting principles, there is a substantial body of jurisprudence in this court that indicates how they are to be reconciled.  Because the possibility of a defence of diminished responsibility was only formulated by the Commission itself, and apparently not contended for in Mr Sharp's new advisers' submissions, the authority on this very point does not appear to have been put to them.  It is unfortunate that when, of its own motion, the Commission decided that the matter of diminished responsibility should be pursued, that authority was not drawn to the attention of the Commission by its legal staff.  
28.	The relevant authorities can be shortly summarised.  We did not in the end understand Mr Travers, who argues this case for Mr Sharp, to dissent from their effect, but it is important to set them out.  First, guidance was given by Lord Taylor, Chief Justice, in the case of Ahluwalia 96 Cr.App.R 133 at page 142.  Lord Taylor said this in a passage quoted in Arnold:
"Ordinarily, of course, any available defences should be advanced at trial.  Accordingly, if medical evidence is available to support a plea of diminished responsibility, it should be adduced at the trial.  It cannot be too strongly emphasised that this court would require much persuasion to allow such a defence to be raised for the first time here if the option had been exercised at the trial not to pursue it.  Otherwise, as must be clear, defendants might be encouraged to run one defence at trial in the belief that if it fails, this court would allow a different defence to be raised and give the defendant, in effect, two opportunities to run different defences."
The court in Arnold 31 BMLR 38, distinguished Ahluwalia, as they realised they needed to do, by saying:
"... by the time the matter came to the Court of Appeal, the appellant had placed the relevant factual evidence before the Court of Appeal and given a frank explanation of why the relevant issue had not been raised at the trial."  
We hardly need comment that that is not so in this case.  
29.	Secondly, the earlier case of Straw [1995] 1 All.ER 187.  It is sufficient to read the headnote:
"When the applicant was called on to consider her plea to a charge of murder she was sufficiently capable on the medical evidence of pleading, she had been fully advised as to her position with regard to a plea of manslaughter on the ground of diminished responsibility and she was therefore capable in law of taking a decision as to how her case should be put before the court.  Accordingly, it would not be permissible for the applicant to change her mind following conviction on the murder charge and apply for leave to introduce a plea of diminished responsibility."
We comment there that the court placed weight on the fact that Miss Straw (as is the case with Mr Sharp) had been held to be fit to plead.  Later authority, including the case of Weekes to which we shall come, does not regard that as being a necessary condition.  
30.	We then go to the case in this court of Borthwick [1998] Crim.L.R 274.  The fresh evidence in that case was admitted, but the court said this:  
"The Court was alive to the fact that it must not admit the evidence simply in order to allow B to run a different defence in front of a second jury.  But if there was overwhelming or clear evidence that a defence of diminished responsibility would have succeeded and that it was the mental illness itself that caused the defence not to be run, the interests of justice would seem to require the substitution of a manslaughter verdict, or at least a retrial."
31.	Most recently in Weekes [1999] 2 Cr.App.R 520 this court returned to this question, emphasising that each case turned on its own facts and also emphasising that a finding of fitness to plead was not necessarily dispositive.  The court then said this at page 529D, after extensive quotation from the transcript in Borthwick:  
"We respectfully endorse all that was said in Jones (Steven), Shah and Ahluwalia as to the crucial obligation of a defendant to advance his whole case before the jury.  We draw attention to the fact that in the present case the evidence of diminished responsibility was both unanimous and accepted by the Crown.  If it were disputed by the Crown it would no doubt be very unlikely that it would subsequently be in the interests of justice to admit it in this Court, with the consequence that a retrial became necessary.  Further, in the present case there is evidence both plain and undisputed that the defendant's decision not to allow the issue of diminished responsibility to be canvassed was significantly affected by his mental illness.  That does not appear to have been the situation as the Court understands the matter in Straw, though it was the case also in Borthwick.  Lastly, although as Borthwick shows, an exceptional case may arise, we think it much less likely that it will be in the interests of justice to admit evidence of diminished responsibility which comes into existence only after the trial, rather than was unanimous and undisputed at the time of trial.  The former case is, we think, likely to founder on the principle explained in Jones and (Steven) and Ahluwalia."
32.	We draw from those authorities the following guidance.  First, we are not able to agree with the view that the Commission appears to have taken that the inhibition on running a different defence on appeal is limited to cases where the original decision was in some way dishonest or manipulative, or one purely of tactics.  It is clear to us from the observations of Lord Bingham that he required an objective comparison to be made between the defence advanced at trial and that on appeal.  Secondly, it is only going to be in very exceptional cases that a different defence can be adduced.  Thirdly, that will normally only be the case, as Schiemann LJ indicates in Weekes, where the original evidence was indeed available at the trial.  That is not this case.  Fourthly, the criteria that will be looked for before an exceptional case can be accepted are (i) that the availability of the diminished responsibility defence is effectively unchallenged or at least certainly not controversial; and (ii) that there is an explanation in medical terms for any decision by the defendant not to run that diminished responsibility case at the trial.  In this case, the question of whether Mr Sharp was suffering from diminished responsibility, either by reason of Halcion alone or by reason of the effect of Halcion on an underlying psychological or personality condition, is highly disputed by very distinguished psychiatrists.  Further, the evidence cries out that it was Mr Sharp who decided that this case should not be run.  It was available to him, whether through Halcion or whether through the observations about his general psychiatric situation that were made by Dr Scannell.  It was he who decided not to run it.  There is not a shred of evidence, and no attempt has been made to produce evidence, to suggest that that decision was caused by the underlying psychiatric problem. Nor, we are bound to say, in view of what we have been told of the effects of Halcion, would we find such evidence plausible if it were produced.  
33.	We therefore have to say, looking at the authorities, that this case comes nowhere near being the sort of case in which the court would hear further evidence, or be minded to accede to a defence on the basis of that evidence.  We are quite confident that had the Commission had its attention drawn to the authorities that we have set out in this judgment, which it does not appear to have had before it, it would have taken a very different view of Mr Sharp's application.  In any event, the application having been made and the appeal brought, for the reasons given the appeal is dismissed.