Saturday, December 15, 2012

Double take here....


Somebody sent this through as a comment. I hope Don Mathias doesn't mind me using it, I will remove it if so. It deals with the misapprehension abroad that Ian Binnie wouldn't have looked at the evidence as a complete picture, but also in isolation where in his report he put some issues aside. It would not be possible to not look at the complete 'picture' in over 10,000 pages it would have been a repetitive theme and something needed to be taken into context when considering individual points. It also highlights that Fisher did not comment on whether Binnie's decisions were right or wrong.

Bain, Binnie, Fisher, Bayes – how should judges reach conclusions?

Once again out little nation is divided over the Bain case and its consequences. The current controversy is over whether the report by retired Canadian Supreme Court Justice Ian Binnie should be accepted or whether its review by retired New Zealand High Court judge Dr Robert Fisher QC has cast doubt on its conclusions.
We have seen here recently how appellate judges on the same court can differ sharply over what conclusions can be drawn from the evidence in a case. Is there a right way to arrive at conclusions from facts?
In trials juries are given little guidance on how to reason, other than being told that the drawing of inferences is a process of using logic and common sense, something people do all the time in their daily lives. It is assumed that people have an innate ability to reach proper conclusions. This assumption must be correct. We tend to be right more often than we are wrong, but without examining why.
Judges have to give reasons for their decisions. The process of articulating reasons imposes a discipline on judicial thinking, and until that process is completed a judge may not know what conclusion is going to be reached. An echo of this is the instruction to jurors to keep an open mind while evidence is being given.
Bayesian analysis is useful in revealing or guarding against errors of logic when inferences are drawn from facts. Dr Fisher has used this in his report. This does not mean that Ian Binnie was wrong to not use it in his. Most people have no idea what Bayes’ Theorem is and they infer correct conclusions without using it. The interesting question is whether Dr Fisher has revealed any error of logic that was sufficient to make Ian Binnie’s conclusions wrong.
My assessment is that the only candidate for being an error of this significance is Dr Fisher’s claim that Ian Binnie failed to consider the evidence cumulatively as opposed to by taking each item at a time. Ian Binnie has denied, in an email to the Minister of Justice that has been published, that he made this error.
It would be astonishing if Ian Binnie had made this mistake. Judges habitually stand back after evaluating the probative value of particular facts and look at the overall picture. That is done to enable a conclusion to be drawn from the combination of the probative values of the facts. This process is what is done instinctively when people exercise their judgment.
There are all kinds of influences, revealed by psychologists, which can cause people to make mistakes. A Bayesian approach to inference drawing can counteract those, but its best application requires extensive statistical information, far beyond what is usually available in court cases.
Nearly all judicial decisions are made only on the balance of probabilities. This standard recognises that we can seldom be certain we are right, and that in the interests of finality a decision on the balance of probability is good enough. Hugely important decisions are regularly made in the courts on that basis.
It is significant that Dr Fisher has not endeavoured to decide whether Ian Binnie’s conclusions were right or wrong, but that he correctly restricted his report to Ian Binnie’s method. Plainly, if Dr Fisher were to go further in a subsequent report, he would apply the Bayesian approach. But that should lead to the same conclusions that Ian Binnie reached unless radically inappropriate assessments of likelihood were made by Ian Binnie over critical facts to such an extent as to influence the result of considering the combined probative values of all the relevant facts.
I was surprised when reading Ian Binnie’s report at how he treated the evidence of the luminol footprints. Depending on the length of those footprints, they could have removed the case from being an exercise in assessing probabilities and made this a case of direct evidence of innocence. That was recognised in the Privy Council hearing, as both sides agree. However Ian Binnie has been generous to the prosecution by recognising some doubt over the accuracy of the measurement made by the police officer of the footprints on the carpet at the scene. Whether the measurement could really have been susceptible to error to an extent sufficient to cast doubt on who left it there is a matter of judgment for those who have looked at the evidence that was given on this point.

6 comments:

  1. http://tvnz.co.nz/national-news/us-witness-behind-ewen-macdonald-s-defence-5128917

    When Ewen Macdonald was acquitted of murdering Scott Guy, few people knew an American forensics expert had played a key role in his defence.
    In his first New Zealand interview, Ohio-based forensic podiatrist Michael Forman explained how the Crown's main evidence - a pair of dive boots worn by the killer - could not have been worn by Macdonald.
    Scott Guy's blood ran into boot prints left by his killer when he was fatally shot in July 2010 .
    Footprints and dive boots In his opening statement, Crown prosecutor Ben Vanderkolk said footprints with a ripple pattern were found around the murder scene.
    The Crown alleges the prints were made by Macdonald, while wearing size nine Proline dive boots he had since disposed of
    The crown said size nine Proline dive boots belonging to Macdonald were the right size and had the same distinctive wave pattern.
    But the defence counted only 29 wavy rows on a sample size nine boot and there were more than 30 wavy rows in the prints at the scene.
    Macdonald's lawyer Greg King emailed Forman photographs of the prints and plaster casts taken at the gate of the Guy family farm.
    Forman revealed the crime scene imprints matched boots that were size or 11 or 12, fitting a man who was likely to be much taller than Macdonald.
    The jury threw out the Crown's case and found Macdonald not guilty of the murder.


    Justice Binnies Report

    2. David Bain’s bloody socks and clean running shoes
    42. When found by the Police David Bain was wearing a t‐shirt, rugby shorts and socks.
    There was some smearing of blood on the bottoms of his socks.

    43. David Bain says the blood stains were picked up by innocent transfer as he went about
    the house after completing his paper route, going from room to room looking in vain for signs
    of life from other family members.

    The Crown Law Office says:
    (i) The socks became bloody when David killed his mother and siblings before
    leaving on his paper route. However, when the interior of his running shoes was
    examined by forensic scientists at the ESR laboratory no blood stains were found
    on the inside of the Laser running shoes. One would expect such stains to be
    present if the prosecution theory were correct that he had been running in them
    with bloody socks for about an hour;

    Quite clearly investigations into both of these tragedies were nothing more or less than pathetic.

    This is what Judith Collins is defending with her hidden agenda.

    ReplyDelete
  2. There is an interesting discussion on the respective approaches of Binnie vs Fisher at http://www.pundit.co.nz.

    ReplyDelete
  3. http://www.pundit.co.nz by Ross on December 14, 2012

    But couldn't you be mixing up cause with effect there?
    Well, I could be but after reading the transcript of his interview witth Bain, I'm not so sure. Bain comes across worse than I would've expected. Yet Binnie seems to accept what Bain tells him, despite the latter's sometimes far fetched and contradictory comments. I agree with Fisher that Binnie has too readily accepted Bain's version of events. Would someone who was truly detached be inclined to do that?


    The above post by Ross on Dec 14, 2012 is as far as I have read so far and as a result of this post quite frankly don't see any good reason to carry on reading.
    The problem I have with people like Ross is (I don't mean to be disrespectful) that he has obviously in mind a conclusion to all of this that is that David Bain is guilty of the murders.

    He says 'bain comes across worse than I would've expected'.

    How bad did he expect David Bain was going to be? Why wouldn't he expect David Bain to be himself and not how he would want him to be? His comment is quite bazaar.

    He then went on the say 'Yet Binnie seems to accept what Bain tells him, despite the latter's sometimes far fetched and contradictory comments. I agree with Fisher that Binnie has too readily accepted Bain's version of events'.

    Ross makes it sound as though J Binnie first interviewed David Bain then examined the screeds of information put in front of him looking for evidence that matched with comments David made during his interview with him. Had he considered that J Binnie may have read everything made available to him before he interviewed David Bain? I don't think so.
    He then finished with 'Would someone who was truly detached be inclined to do that?

    The way he has slanted his comments shows quite clearly he is not detached either. His attachment to all of this and his desire to see a conclusion that suits his, in particular, has obviously clouded his judgement.
    Judith Collins also suffers from not being able to distance herself from her personal desire to see this through to a conclusion that suits her attachment the Bain tragedy.

    ReplyDelete
  4. Nos when you step back for a moment and look at the whole Bain affair in total from start to finish (or up until this point) what was the most uncomplicated crime scene ie when the police arrived at 65 Every Street they had at their disposal the MURDERED the MURDERER and the MURDER WEAPON the whole affair only became complicated when Joe Karam became involved.

    If you take a look at the noisiest anti David Bainers in this Kent Parker, Vic Purkiss, L Kennard, Mike Stockdale, Judith Collins and so on (I am sure you could add to this list) their motivation appears to be their deep setted hatred of Joe Karam.

    Just because David Bain found himself supported by someone who was passionate about David's innocence and could afford to his support DOES NOT make David Bain guilty.

    The chap above has fallen into the same trap the police dough themselves into by deciding on David's guilt them manufacturing an argument to suit.

    ReplyDelete
  5. Don Mathias' blog has since been updated. In the update, he reasons it through to a conclusion that in fact, using proper reasoning (Bayesian reasoning, as noted by Fisher to be the correct approach, and which Binnie certainly seems to have used quite properly, although I the way he communicated it allowed the criticism) actually produces a result of INNOCENT BEYOND REASONABLE DOUBT (please excuse the capitals, they are for emphasis).
    As Dr Mathias points out, the footprint evidence, even allowing for the measurement inaccuracies, is pretty unequivocal that Robin made those footprints. The Solicitor-General acknowledged that if even one of those footprints was Robin's, the case against David collapsed. If Robin made those footprints, then every other piece of circumstantial evidence MUST have an innocent explanation, regardless of how they looked at the time and continue to look to those who are committed to their belief in David's guilt. There has been some rather feeble attempt by the rabid amateurs to argue that Hentschell's statement is better evidence than that of the experts, but that only shows an unsurprising profound ignorance of what determines the quality of legal evidence. By the Daubert criteria, Hentshell's statement has no value at all as evidence.

    ReplyDelete
  6. Looking at the recent posts on the Bain threads on kiwiblog, it is quite clear that the majority of the contributors have no understanding of probabilistic reasoning in law.
    More worryingly, it seems from Fisher's report that he also has little understanding of it. He cites Bayesian reasoning, but then gives an example of armies and gladiators which show quite clearly that he does not understand it. This lack of understanding, I assume, explains why he claims that Binnie did not weigh up the evidence as a whole - which in fact he quite obviously did.
    I have reviewed Fisher's reports on other compensation claims for his decision processes in light of this, and there is absolutely no evidence of him having applied Bayesian analysis or even the principles underpinning them. He appears to have operated a far less sophisticated and less independent approach.
    This is very alarming. It means that knee-jerk response is operating at the highest levels in New Zealand. Which in turn means the chance of dispassionate fairness is almost nil. This affects not just Bain, but potentially every contested case before the courts.

    ReplyDelete