I had a case for diminished responsibility.

JOANNE DENNEHY, LETTER TO THE AUTHOR, 24 FEBRUARY 2014

Combined with all of the overwhelming physical and circumstantial evidence stacked against her, with Joanne Dennehy having maintained her guilt from the outset, her legal team had just one defence and it would have been a flimsy one at that. They would use her previous psychiatric evaluations in an attempt to prove some form of mitigation: that she had committed her crimes while labouring under a mental illness, therefore there was the defence of diminished responsibility.

Dennehy had been twice diagnosed by psychiatrists as having a ‘series of acute personality disorders’, however readers will have guessed from the outset that she is not a socially inclined individual – far from it.

David Wilson, Professor of Criminology at Birmingham City University, followed her prosecution and says: ‘It is impossible to say with certainty whether a person is born a killer or becomes a killer, but most criminologists believe that it is a messy combination of the two.’

This statement, of course, boils down the Nature versus Nurture argument, so popular a decade or so ago. Today, we are inclined to quantify it as Nature and Nurture – a mix of both, if you will.

Professor Wilson also says: ‘A person can be born with a genetic makeup that means they have the potential to kill – but it is not a given that they will go on to fulfill that potential. For that to happen, certain sociological and psychological circumstances need to be in place. In Dennehy’s case, they clearly were. She had disengaged from all the institutional structures that usually provide a stabilising influence – family, education, work, and so on. In addition, she was giving full rein to her paraphilia – her obsessive interest in atypical sexual practices – with her use of hardcore pornography and her pursuit of sadomasochistic sex. And the dividing line between reality and fantasy was further blurred by her persistent use of drugs. She also had a strong narcissistic streak – she craved notoriety and she enjoyed the power that killing gave her, and which she lacked in every other area of her life.’

However, for criminologists seeking to untangle Joanne’s twisted mind and the nature of her crimes, her descent into barbarism is all the more shocking given the respectable nature of her childhood, a brief history of which has already been outlined in this book. Therefore, we can only speculate on how her mind worked, starting with the psychiatric evaluations of Dennehy when she was twice sectioned under the Mental Health Act. Summing this up, if a wax effigy of her were to be displayed in the Chamber of Horrors at Madame Tussauds, it would wear a label saying:

With all this in mind, one might reasonably ask whether Joanne Dennehy is mad, sad or bad, beginning with questions as to her sanity and whether she was mentally competent to stand her trial. There are, in fact, two ‘insanity’ defences:

That, because of a disease of the mind, an offender does not know the nature and quality of the act; and

That even if one did know the nature and quality of the act, because of a disease of the mind one did not know it was wrong.

In pleas of diminished responsibility – as Dennehy herself has alluded to – it is for the defence to establish a defendant’s insanity ‘on balance of probabilities’. It is for the jury to decide, and the guidelines for their use are embodied in the M’Naghten Rules, which in part state: ‘Every man is presumed to be sane, and to possess a sufficient degree of reason to be responsible for his crimes, until the contrary be proved to their [the jury’s] satisfaction’.

On 20 January 1843, in Downing Street, a Glasgow woodworker named Daniel M’Naghten drew a pistol, then shot and killed Edward Drummond, secretary to the Prime Minister, Sir Robert Peel, who was, ironically, the founder of the Metropolitan Police. The lead ball had been intended for Sir Robert himself but M’Naghten seems to have been unfamiliar with the Prime Minister’s appearance and to have shot the first likely candidate.

At his subsequent trial before judge and jury at the Old Bailey, it transpired that he had had, with no apparent justification, an unreasoning suspicion that ‘Tories’ were persecuting him. Not only had murder had been committed on the open street, but Her Majesty’s PM could so easily have been the victim. There was then a certain tinge of self-interest in the disquiet voiced by Parliament when the jury returned a verdict that M’Naghten was insane and should therefore be merely confined to a mental hospital. Great, too, was the public discomfort at this verdict, and it was subsequently contested in the House of Lords.

Their Lordships decided to require Her Majesty’s judges to advise them on the matter – an ancient right of the House, though seldom exercised. The joint answer given by fourteen judges formed what became the M’Naghten Rules and reads in essence as follows:

Joanne Dennehy therefore knew the nature and quality of her acts. She understood that what she was doing was wrong so she was mentally competent to plead her case and stand trial, but what of her claim that she had a case for diminished responsibility?

Borrowed from the law of Scotland dating back to 1867, the Homicide Act 1957, s. 2, introduced into UK law a new defence for murder known as ‘diminished responsibility’, which entitles the accused not to be acquitted altogether, but to be found guilty of manslaughter. In the US it is called ‘Second Degree Homicide’. By s. 2 (2) the Act expressly puts the burden of proof on the prisoner and it has been held that, as in the case of insanity, the required standard of proof is not beyond reasonable doubt but on balance of probabilities. Therefore consideration of this defence is, strictly speaking, out of place here for it is not a general defence but applies only to murder. In practice, however, the scope of the new defence is almost the same as insanity, for the Rules themselves are rarely relied on outside murder cases. Except in murder, the prospect of indefinite and possibly life-long confinement in a facility such as Broadmoor is far worse than the ordinary punishment for the crime. Similarly, it is reasonable to suppose that defendants generally prefer a conviction for manslaughter to an ‘acquittal’ on the grounds of insanity.

For her part Dennehy did not plead diminished responsibility although she had told me in her 24 February 2014 letter that she may have had this defence available to her. It was not for the prosecution to interfere, and it is highly doubtful whether Mr Justice Sweeney had the discretion to call evidence of diminished responsibility. Even if he had, he could not call such evidence against the wishes of Dennehy, who had just made her intentions perfectly clear in telling him to ‘Fuck off!’ Therefore, her only option now is to appeal and a U-turn on confession is unusual.

According to Shula de Jersey, a solicitor from Slater & Gordon lawyers, anyone who has been convicted of a crime has the right to make an application to the Court of Appeal. In this situation – where the person has already pleaded guilty – there would have to be grounds for appeal. For example, the person could claim they made a confession or confessed under duress. In Dennehy’s case she admitted her guilt the moment she was booked in at Hereford and against the advice of her legal team, she maintained her guilt throughout.

‘This is a very unusual situation,’ says Shula de Jersey, ‘and I have never heard of someone admitting a murder then retracting it. The court would look at the evidence and decide whether to overturn the conviction. Even if it was overturned, the person who is suspected could still be charged as police may investigate further and pass a file to the Crown Prosecution Service, which would then consider if charges could be brought.’

This would only happen if it was in the public interest and there was a reasonable chance of a conviction. Prosecutors would have to take into consideration that the individual making the allegation is serving life in prison and may not be considered a reliable witness.