Tuesday, January 20, 2015

Book Review: The Singular Universe and the Reality of Time, by Unger and Smolin

The Singular Universe and the Reality of Time by Roberto Mangabeira Unger and Lee Smolin, CUP, 2015 brings to our attention a likely explanation for the lack of progress in cosmology since the 1970s. The book will be of interest to some lawyers (Unger is, among other things, a legal theorist) for the light it may shed by analogy on some aspects of legal theory.

This is really two books under one cover, both advancing the same general argument, with Smolin addressing some scientific topics at a level of detail, but not at undue length, that is beyond what general readers would understand. The first part of the book is by Roberto Mangabeira Unger, and the second, from page 349 (if my Kindle app is accurate) by Smolin.

Both authors wrote the introductory remarks, from p x to p xx.

“Cosmology is the study of the universe as a whole, beyond which, for science, there lies nothing.” (p xx).

There are “three big questions about cosmology”, stated by Smolin (401) as:

“What happened at very early times, closer to the initial singularity? What will happen to our universe in the far future? What is there, very far away from us, outside our cosmological horizon?”

Cosmology can only answer these by way of being a science. A science is (501)

“... only about what can be conclusively established on the basis of rational argument from public evidence.” [footnoting Smolin, The Trouble With Physics, 2006, a book that I can recommend]

Incidentally, and I digress for a moment: in The Trouble With Physics Smolin gives us (293) Feyerabend’s amusing observation that he could win any argument in philosophy simply by using skills he had acquired as an actor. “This made him wonder whether academic success had any rational basis.” Drama-queen teachers take note!

No progress has been made on important cosmological questions, and Unger and Smolin argue that this is because scientists have used incorrect assumptions. Questions include: why, when important equations have many solutions, is only one accepted as correct? Why are there three spatial dimensions? Why do the so-called universal constants have the values they do? Why is there life? How did the universe come to what appears to be thermal equilibrium at a single temperature? Why do we assume that the laws of physics apply throughout the universe (including the part of the universe we cannot yet detect), and in an unchanging way?

Most of us will remember wondering why Einstein started his special theory of relativity by assuming that the speed of light in a vacuum is constant and cannot be exceeded. True, experiments suggested that that was so, but should those results be applied everywhere and always? His other basic assumption was that the laws of physics apply uniformly for all frames of reference. Do they, and why?  And his removing of time from its role as a universal and uniform measurement may well produce results that appear to be correct in the part of the universe we can currently detect (even if only by measurement to a level of precision only expensively achieved), but everywhere and always?

Unger and Smolin reinstate time as the absolute backdrop to physical events (52), not an accessory to space (53), they assert it is real (354) and it enables recognition of what they assert will be found to be the evolution of physical laws (357). It also gives meaning to causation: if time is not real, causality (the influence that a state of affairs exercises over what follows it) cannot be real (35). However, the uneasy reader might say, it is not explained how this absolute time is to be measured, and how the measuring standard might change as the physical laws evolve. Still, the point seems to be that time does not vary within a frame of reference, or between frames of reference, or historically compared to any measurement that is known. Where this leaves Einstein is not made clear (at least to me, other people are probably not troubled at all), unless the modification is confined to the unknown part of the universe.

Three central ideas – or perhaps we could say assertions or axioms - are developed in the book (I summarise from pp 5-16): the solitary existence of the universe (there are not, and have never been and will never be, mulitple universes); time is inclusively real (nothing is outside time, everything changes sooner or later); and mathematics is not a substitute for reality, it should be seen as representing a world eviscerated of time and phenomenal particularity (mathematical relations are timeless and of a general character, and indeed are useful to a point, but they do not model a universe in which time is real).

At the very least this book illustrates what can be done when a discipline reaches a dead-end. Fundamental assumptions are re-examined and changed.

One of the joys of looking at the problems that have arisen in another discipline is that ideas applicable to law may be brought to mind. Even now, while I half-listen to New Zealand playing Sri Lanka in a one-dayer at Nelson.

Is there an unknown law that has yet to be perceived?
Obviously, yes. All the things that have yet to be invented are potential subjects for new law, and new kinds of laws. It is impossible to imagine what they may be, but we can say that there will be laws that will apply to them. Whether those laws will be recognisable by reference to our current criteria, or whether new criteria for recognising law will evolve, is not known. But we can say that there is no reason to keep our definition of law constant so that it is temporally limited to known conditions.

Does the law apply everywhere?
Courts have had to decide whether constitutional protections apply extra-territorially (for example see the case discussed here on 13 June 2008). There is increasingly a tendency for the law of one territory to be given extra-territorial application, at least as far as the courts of the domestic territory are concerned. And within a territory it seems there is no room for exceptions to the obligation to obey the law; exceptions are within the law, not extraneous to it. The law applies under the surface of the earth and above it, extending into space. Rights may be given over territory on the moon, and beyond. The extent of the application of the law may only be limited by the human imagination. This means it may apply in environments that are little known, raising the question of the extent to which the conditions for application of law are part of the definition of law.

What is progress in law?
Social norms do not have to be laws (see Gardner, Law as a Leap of Faith, reviewed here on 6 July 2013). If procedures are applied to norms, sufficient to make them recognisable as laws, then that is what they are. But some laws are rights, accepted as somehow being of a higher kind than other laws. If that has happened to a norm, the progress is from a non-legally enforceable social convention, to law, to higher law. Increasing recognition of rights suggests increasing opportunity for progress. Law is not static in this regard. Whether rights will continue to increase, or will reduce, is not known, but there is no reason to think that present trends will always apply. To what extent can we expect to be able to prevent, or encourage, change?

Is it useful to ask why a law exists?
People don’t need laws: it is possible to imagine a community that functions without a legal system (Gardner, above, pp 296-301, suggesting that the functions of law can be served by conventions like morality, etiquette, games, and traditions, and law may have different importance at different times in history, and may one day be lost and forgotten).

So what is law for? Convenience, obviously, in settling disputes, minimising conflict, and preventing or making-good harm. Those functions can be achieved by means other than law, so they do not assist in defining what law is. Law is not defined by its use, but by the process by which it comes into existence.

What is the relationship between a law and the environment in which it applies?
The application of a law is different from its definition as law. A law may be a law although the circumstances in which it could apply have never arisen. For example, laws made to apply in the event of natural disasters or epidemics are still laws pending those catastrophes. The law is not imaginary, although its application is. One of the main aims of criminal law is deterrence, and it is made in the hope – optimistic though it may be – that it will never need to be applied.

The environment in which a law applies may change dramatically, while the law stays the same. But this stasis is not essential: the law may be developed, by conventional techniques of legal reasoning, to meet new demands. To what extent is it then the same law as before? Laws, once created, may evolve with the environments in which they are applied.

What is the relationship between law and reality?
Just as in physics mathematics should not be confused with the reality which it is used to explore, so too in law the techniques of legal reasoning should not be confused with the reality to which law has to be applied. Conventional legal reasoning – the techniques of statutory interpretation, the methods of arguing about case law – will not necessarily produce the correct application of law to a particular problem. The life of the law, as has been said, is not logic but experience. Logic, in law, is subject to correction on policy grounds.

To what extent should legal concepts be defined?
The fight in physics is against uncertainty, whereas in law uncertainty can be an advantage. The circumstances in which a law may have to be applied cannot necessarily be wholly anticipated when the law is made, and some judicial creativity in its application should be allowed for, if the law is to remain useful. It is not unusual to find a statute on a subject which itself is not defined, as for example where the Search and Surveillance Act 2012 [NZ] does not define search.

It may not be useful to define concepts when the law’s purpose may have to be applied in circumstances which, at present, are not clearly perceived. We may know what we want, without necessarily knowing when we may want it. Should this desire be expressed as a law?

What are the premises of the rule of law, and should they be the same everywhere?
An idea that has emerged relatively recently is that a fundamental requirement of law is that it should be identifiable, ascertainable, equal in its application, accessible, and, to an extent that is a matter of some debate, consistent with the requirements of a fair trial and other fundamental rights. The debate about this latter point is not about whether trials should be fair, etc, but about whether this requirement of fairness and conformity with fundamental rights is part of the rule of law.

It seems uncontroversial that the law should be ascertainable and equal in its application, but this is not necessarily universally accepted. There has recently evolved the closed-material form of trial, where the defendant is not told what some of the prosecutor’s evidence is. Public interest in security is said to outweigh the defendant’s right to confront and cross-examine opposing witnesses. See further the discussion here on 18 April 2014.

Monday, November 17, 2014

Book review: The Sense of Style - The Thinking Person's Guide to Writing in the 21st Century, by Steven Pinker

I enjoyed most of Steven Pinker’s, The Sense of Style – The Thinking Person’s Guide to Writing in the 21st Century.

My computer puts a green wavy line under the second definite article in that title, apparently because it doesn’t like the capitalisation. Just illustrating that we can all find something to argue about when deciding how groups of words should be written. I could object to the inelegance of the occurrence of two definite articles in so few words, and I could wonder at the ambiguity: who is the thinking person, the author or any reader who finds the book a useful guide?

And arguments can get heated. To deter criticism – rather as Kremlin parades of nuclear missiles averted Moscow’s annihilation – Pinker ends with five things an antagonist should do before engaging. The fifth includes this:

“Psychologists have shown that in any dispute both sides are convinced that they themselves are reasonable and upright and that their opposite numbers are mulish and dishonest. [Footnoting Haidt, J. 2012. The righteous mind: Why good people are divided by politics and religion. New York: Pantheon, and Pinker, S. 2011. The better angels of our nature: Why violence has declined. New York: Viking, chapter 8.]”

Squabbles about being right or wrong are beside the point. The point is style, not grammar. And Pinker concludes by saying that the reasons to strive for good style are:

“to enhance the spread of ideas, to exemplify attention to detail, and to add to the beauty of the world.”

And how to achieve good style? Pinker describes his own writing method, presumably used for this book: rework every sentence, revise a chapter two or three times before showing it to anyone, revise again at least twice in response to feedback, then give the whole book “at least two complete passes of polishing” before it goes to the copy editor for a couple more rounds of tweaking.

Good style doesn’t come easily. And what is the thing that all this revision is trying to get into the writing? Pinker gives plenty of examples of how writing can be improved. In the end, however, all that can really be said by way of defining good style, it seems to me, is that it feels right, and in the case of a revision it feels better than what went before. And this improvement would be accepted by most adults who have English as their first language and who appreciate good writing (the thinking people of his title). Read aloud, to get syntax right so that readers don’t stumble: “laboratory studies have shown that even skilled readers have a little voice running through their heads the whole time.” If it doesn’t sound right it’s not good style.

In one – what is for me significant – respect I find Pinker’s style repellent. I suspect his ears (as he says in relation to a different topic) have “been contaminated by a habit ... to avoid spitballs from the Gotcha! Gang.” It seems to me that his ears have been contaminated in the academic environment by the requirement, appropriate though it may be during a developmental stage of young people’s education, to avoid the sexism of using he to include the female gender, by using he alternately with she, or by using the phrase he or she, or by using their to refer to a singular of either gender.

I agree that sexist language should be avoided, but the right way to do it is to revise until the need for reference to gender disappears. I agree with Antonin Scalia on this (see my review of Scalia and Garner, Making Your Case – The Art of Persuading Judges).

Pinker begins (according to my Kindle app this is p (iv)) by telling us that he will “avoid the awkwardness of strings of he or she ... [by] consistently referring to a generic writer of one sex and a generic writer of another. The male gender ... will represent the writer in this chapter; the roles will alternate in subsequent ones.” But later (p 260) he refers again to science: “Experiments that measure readers’ comprehension times to the thousandth of a second have shown that the singular they causes little or no delay, but generic he slows them down a lot.”

So generic he is bad. Presumably generic she is too. So Pinker’s plan was to alternate bad style chapters with other bad style chapters.

Although he acknowledges that he or she is clumsy (p 256), his plan leads Pinker to do worse by alternating male and female pronouns, even in the one sentence (p 29): “The writer can see something that the reader has not yet noticed, and he orients the reader’s gaze so that she can see it for herself.”

This would have been better: "The writer can see something that the reader has not yet noticed, bringing it to the reader’s attention." And even better: "The writer can bring something new to the reader's attention."

And sillier too is the image one gets of Pinker marking a student’s paper, when he says that (p 28) a “college student who writes a term paper is pretending that he knows more about his subject than the reader and that his goal is to supply the reader with information she needs ...”.

Better would have been: "a college student who writes a term paper is pretending to know more about its subject than the reader and that the goal is to supply the reader with needed information." Even better: "a college student who writes a term paper is pretending to tell the reader something new."

My suggestions are not perfect, and I’m not calling Pinker mulish, but they point to directions for further revisions.

This narrow point of objection to Pinker’s style may not be shared by you (I have done this sort of thing before), and it doesn’t really diminish the value of the book. A good guide for everything except avoidance of sexist language.

Monday, November 03, 2014

Book review: Lord Mansfield - Justice in the Age of Reason by Norman S Poser

If you are not yet in love with eighteenth century London, Lord Mansfield – Justice in the Age of Reason by Norman S Poser will get you started. If, as mine did, your infatuation began with Boswell’s The Life of Samuel Johnson, LL.D., you will be well prepared. But Poser’s account is so straightforward and clearly written that there is really no threshold of preparation to be overcome.

Both Boswell and Mansfield (born William Murray) were social climbers. Both were lawyers. Both were Scottish. They knew each other. In April of 1772 they appeared on opposite sides in an appeal in the House of Lords, and Murray won. Murray was educated in England, after at age 13, and unaccompanied, he rode a horse to London from Edinburgh, never seeing his parents again, to attend Westminster School. Johnson observed to Boswell: “Much may be made of a Scotchman, if he be caught young.” Boswell was educated in Scotland and Holland.

As a lawyer Murray had an appreciation of Roman law and as a judge he was inclined to be guided by principles rather than rules, introducing what some thought was an alarming unpredictability into the common law. Poser summarises this (p 402):

“His study of the great philosophers of law instilled in him a belief that all law was based on morality, reason, and human nature, which were the same everywhere, even though customs, mores, and traditions differ from country to country.”

Poser’s review of the courts in Westminster Hall is extraordinarily clear, and it is only regrettable that those who taught me legal history, and who wrote the textbooks, were not so interesting. The times were ones of, by our standards, corruption. Judicious payments could lead to judicial office. Judges kept for themselves a proportion of the court fees in cases they heard. Lord Mansfield – he insisted on being ennobled as a condition for his acceptance of the position of Chief Justice of the court of King’s Bench – on occasion was in the House of Lords when appeals from his own decisions were heard. His fear of exposure for a youthful indiscretion, which could have led to accusations of treason, led him to be unduly concerned with placating those in political power. But this was widely known anyway, and he was occasionally subjected to harsh criticism in print.

Murray was so able a lawyer, particularly because of his learning and his eloquence, that he quickly became a leader of the profession. He amassed a fortune, even before going to the bench – indeed it was probably his potential financial sacrifice that gave him the leverage to demand the peerage. He invested in mortgages on properties owned by aristocrats. He was incurably ambitious. As Horace Walpole wrote, “he knew it was safer to expound laws than to be exposed to them.”

He was an autocratic judge, although unafraid of admitting that he had been wrong. Poser gives us this:

“when asked why he had changed his mind on a particular point of law, he answered that it only showed that he was wiser today than he had been the day before.”

I can’t help but wonder whether Bramwell B was thinking of this when he said, in Andrews v Styrap (1872) 26 LT 704, at p 706: “the matter does not appear to me now as it appears to have appeared to me then”.

Mansfield worked extremely hard as a judge. He sat long hours and kept cases going even after he had gone home: juries would sometimes have to visit him in Bloomsbury Square to return their verdicts. His instructions to juries were alien to our standards, and he had a rather flexible attitude to penal laws he didn’t like. On one occasion he told a jury that (pp 352-353)

“... These penal laws were not meant to be enforced except at proper seasons, when there is a necessity for it; or, more properly speaking, they were not meant to be enforced at all, but were merely made in terrorem ...
“   Take notice, if you bring him in guilty the punishment is very severe; a dreadful punishment indeed! Nothing less than perpetual imprisonment!”

Americans make a hero of Mansfield, and of his contemporary Blackstone, because they inherited the common law as it then was. More realistically, he had characteristics that are all too familiar: he was erudite, opinionated, a bully, a climber, avaricious and ambitious, acquisitive and greedy. He ended his years at his (then) country house, Kenwood in Hampstead, obese and arthritic, having clung to office until his inability to write forced him into retirement. In some ways, too, he was very kind, but he had a lot to be kind with.

Although he had, and apparently enjoyed, a long marriage, there were no children. As a ladies' man he seems to have fitted Clive James's description of Isaiah Berlin:

"Sexually inoperative but incorrigibly flirtatious, he loved the high-born ladies, who loved him right back, although his paucity of physical response - a desert under the ocean of talk - led several of them to despair ..."

Boswell, in his journal entry for 11 April 1773, describes a conversation with Mansfield (who would live another 20 years, dying at age 88):

“He is all artificial. He affected to know little of Scotch appeals when over. I catched him ... [showing that] he well remembered what he affected not to remember. It is unpleasant to see so high an administrator of justice such a man.”

Friday, October 03, 2014

Book Review: Peter Gill, "Misleading DNA Evidence: Reasons for Miscarriages of Justice"

Every criminal lawyer needs to read Peter Gill’s “Misleading DNA Evidence: Reasons for Miscarriages of Justice” (Academic Press, 2014).

Judges should read it too. It is admirably clear and no expertise is required of the reader. If you have some experience with DNA evidence and Bayesian reasoning you will still find the book useful for its descriptions of how things can go wrong.

Peter Gill is one of the world’s leading experts on forensic DNA. I say ‘one of’ just to be polite to any other contender, for Dr Gill is really the leader.

Things can go wrong (as I so eloquently put it above) because DNA detection is now very sensitive and DNA is everywhere. A typical crime scene will have detectable amounts of DNA from many sources. Partial DNA profiles can be detected too, and this complicates the evaluation of mixed samples. Investigators can contaminate a crime scene, transferring DNA from one thing to another, with even latex gloves being vehicles for transfer. Detection of DNA does not mean that it is necessarily present because it was in a body fluid present at a crime scene. Samples collected for analysis must be sealed, and gloves changed, so that no transfer should occur between them, and in the laboratory the risk of transfer between suspect and scene samples must be minimised. There should be studies of the risks of contamination within a laboratory, and these should be done without the knowledge of those who work in that laboratory.

Courts tend to leap to conclusions that are not scientifically sound. Inferences that could be tested experimentally are often drawn without that evidence. A common example may be the assumption that a defendant’s DNA on a murder weapon found at a crime scene was only on the weapon and was not also on a  number of other items which would innocently explain why it was also on the weapon; what the media refers to as the Amanda Knox case is an illustration that Dr Gill uses to make this point: the defendant’s DNA on a knife, allegedly the murder weapon, in a kitchen drawer, was given significance it may not have deserved in the absence of evidence of whether her DNA was also on other items in the drawer (which it surely would have been as she used the kitchen).

I don’t want to spoil your enjoyment of this book by saying more. The Kindle app version, giving coloured text, has links that are easy to navigate, including links to some of the cited technical papers that are available online. It is a book that should be discussed with expert witnesses, whether they are relied on by the prosecutor or by the defendant.

Sunday, August 24, 2014

Wrapping up

And that was ten years of commentary. Just a consequence of having the radio on while working at my desk on 25 August 2004, and hearing a computer person being interviewed about how to start a blog.

600 commentaries. Ovid’s self-rebuke comes to mind:

Cum relego, scripsisse pudet, quia plurima cerno, me quoque qui feci judice, digna lini.

Saturday, August 16, 2014

A defendant's liability for Parliament's mistake

A couple of statutory interpretation questions were answered in Beezadhur v The Independent Commission against Corruption & Anor (Mauritius) [2014] UKPC 27 (7 August 2014), one unanimously, the other not.

The relevant provisions were s 5 of the Financial and Anti-Money Laundering Act 2002 [Mauritius], which prohibited transactions in cash above a fixed amount but subject to exemptions, and s 2 which defined exempt transactions in terms which, relevantly here, included the phrase “lawful business activities”. This legislation has, since the result of this case in the Mauritius Supreme Court, been amended by omitting the reference to “business” [4].

The Board agreed that the defendant had the burden of proof at trial on the issue of whether a financial transaction came within a statutory exception to liability, applying the long-recognised [26] policy that this should be no particular hardship because the information would be readily available to the defendant [32], applying R v Johnstone [2003] 1 WLR 1736 para 50 per Lord Nicholls.

The other issue, the meaning of “business” in the relevant statutory exemption, in particular the phrase “the transaction does not exceed an amount that is commensurate with the lawful business activities of the customer”, drew a dissent from Lord Kerr. He favoured a liberal construction, to give a wider exemption, consistently with the shift of the burden of proof to the defendant [39], [40]. The majority held that the policy of the legislation required exemptions from liability to be construed narrowly [22], [23].

This raises, we might think, a more general question: should legislative action, taken before a case has completed its appeal process, to remedy what has been revealed in the lower court to be an unintended consequence of the original enactment, be taken into account in interpreting the original provision for the purposes of the final appeal?

It was accepted [37] that the defendant’s (appellant’s) four deposits, which were retirement savings, were from legitimate sources and his one withdrawal was also for legitimate purposes, and the Board noted that there was no reason to believe that he thought he had broken the law. The legislation was new and it was not clear to what extent it had received publicity. The Bank, it seemed, should have alerted him to the requirements of the Act, and for unknown reasons the Bank had not also been prosecuted. Although there was no appeal against sentence (which had been fines on each of the five counts), the Board indicated that a non-penal disposal could properly have occurred.

The limitation on the Board’s powers, confined here to the appeal against conviction, meant that the defendant had received an unduly harsh sentence (I say “harsh” relative to a discharge; the total fines here amounted to only 1.68 percent of the total monies involved in the charges). Where the penalty imposed is harsher, the jurisdictional limit may be worked around, so to speak: compare Ramdeen v The State (Trinidad and Tobago) [2014] UKPC 7 noted here on 28 March 2014, where the Board riled against a jurisdictional limitation and ordered commutation of a death sentence to life imprisonment. I try not to be sarcastic, but must ask: is it only murderers who get the Board's extended efforts to achieve a just result?

Thursday, August 14, 2014

More on expert evidence

Two decisions of the High Court of Australia yesterday don’t develop the law but they do illustrate how careful everyone should be about expert evidence.

Is the evidence based on specialised knowledge?

In Honeysett v The Queen [2014] HCA 29 (13 August 2014) an expert was called to compare images of the offender obtained from CCTV footage with photographs of the defendant (appellant) taken at a police station. The expert noted some points of similarity. Although in the High Court the respondent suggested that this evidence was adduced only to show that the defendant “could not be excluded” as the offender, the reality was that at trial it had been advanced as supporting an inference of identity. The issue was whether the witness was giving expert testimony.

It seems obvious, now that we know the result, that this sort of comparison could be made by members of the jury for themselves; it did not require any expertise. The limited nature of the evidence in this case was such that it did not involve use of the witness’s expertise in anatomy. Also, the respondent resiled from what in the lower courts had been advanced as engaging expertise: the witness’s experience in viewing CCTV images and making comparisons with suspects; only expertise in anatomy was now relied on [39].

The non-engagment with the witness’s expertise was apparent from a passage in the court below (Macfarlan JA, with whom the other members of the NSW CCA agreed, in upholding the conviction), and quoted by the High Court at [37]:

“In addition to his formal qualifications in anatomy, Professor Henneberg is a person of extensive practical experience in examining CCTV footage, with all its deficiencies, and attempting to identify characteristics of persons depicted in it. The view he expressed on this topic is necessarily subjective and not amenable to elaboration beyond the reasons he gave, or to measurement and calculation.”

(emphasis added by me). This, correctly understood, supported the conclusion that the evidence was not based on specialised knowledge [43]:

“Professor Henneberg's opinion was not based on his undoubted knowledge of anatomy. Professor Henneberg's knowledge as an anatomist, that the human population includes individuals who have oval shaped heads and individuals who have round shaped heads (when viewed from above), did not form the basis of his conclusion that Offender One and the appellant each have oval shaped heads. That conclusion was based on Professor Henneberg's subjective impression of what he saw when he looked at the images. This observation applies to the evidence of each of the characteristics of which Professor Henneberg gave evidence.”

The evidence was not admissible. The Court did not have to decide whether, as submitted by the appellant, to be based on specialised knowledge an opinion must be able to be independently validated [42].

Mere use of technical language does not mean that an opinion is based on specialised knowledge [45]:

“Professor Henneberg's evidence gave the unwarranted appearance of science to the prosecution case that the appellant and Offender One share a number of physical characteristics. [footnote: HG v The Queen [1999] HCA 2; (1999) 197 CLR 414 at 429 [44] per Gleeson CJ; Morgan v The Queen [2011] NSWCCA 257; (2011) 215 A Crim R 33 at 61 [145] per Hidden J.] Among other things, the use of technical terms to describe those characteristics – Offender One and the appellant are both ectomorphic – was apt to suggest the existence of more telling similarity than to observe that each appeared to be skinny.”

What is the witness actually saying?

The other decision, Fitzgerald v The Queen [2014] HCA 28 (13 August 2014) concerns a prosecution case that, it now seems, could hardly have been weaker: a trace of DNA from the defendant (appellant) was found on a didgeridoo located at the scene of a violent attack. The prosecutor, held the High Court, could not exclude innocent explanations for the DNA’s presence and the conviction was quashed and a verdict of acquittal entered.

The error in the courts below was essentially that the expert’s evidence had been misunderstood. In evaluating whether the prosecutor had proved guilt beyond reasonable doubt the High Court referred to the following points [36]:

“On Dr Henry's evidence ... the prosecution's main contention, that the appellant's DNA in Sample 3B derived from the appellant's blood, was not made out beyond reasonable doubt. Secondly, Dr Henry's evidence was not that secondary transfer of DNA was "rare"; rather, she said that a primary transfer is a much more likely source of contact or trace DNA than a secondary transfer, but that nevertheless a secondary transfer of contact or trace DNA is possible. There was no conflict in the evidence that there were at least two distinct occasions ... on which a secondary transfer of the appellant's DNA to the didgeridoo may have occurred. Thirdly, the recovery of the appellant's DNA from the didgeridoo did not raise any inference about the time when or circumstances in which the DNA was deposited there. For those reasons, it could not be accepted that the evidence relied on by the prosecution was sufficient to establish beyond reasonable doubt that the appellant was present at, and participated in, the attack. The jury, acting reasonably, should have entertained a reasonable doubt as to the appellant's guilt. [footnote: M v The Queen (1994) 181 CLR 487 at 493-494.] Alternative hypotheses consistent with the appellant's innocence, in particular the hypothesis that Sumner [co-defendant] transferred the appellant's DNA to the didgeridoo on Sumner's first visit to the house on the day in question, were not unreasonable and the prosecution had not successfully excluded them. As the evidence was not capable of supporting the appellant's conviction for either offence, no question of an order for a new trial arose.”

Other cases on expert evidence

See also: Dasreef Pty Ltd v Hawchar [2011] HCA 21 (22 June 2011), discussed here on 22 August 2011, and on various types of expert evidence: fingerprints here on 27 January 2006, drug couriers here on 25 February 2014, hypnosis here on 2 February 2007, blood alcohol here on 18 April 2008, sexual assault injuries here on 18 June 2010, the dangers of manipulation of expert evidence here on 26 June 2009, sounds on a recording here on 12 June 2009, unfair criticism of an expert by counsel here on 28 May 2009, and (a brief mention, see the case for details) qualifying as an expert here on 23 January 2006.