Neuberger: A Scientific rationale lends depth to legal reasoning but vice versa? #Forensics

On the other hand, a legal dispute appears to proceed on an almost reverse basis; a legal case starts with already established laws, which each party applies to a series of facts with a view to creating a hypothesis, which then becomes that party’s case, and the judge then decides which of the two cases she prefers. And the validity of published scientific discoveries can be confirmed or falsified by repeating the published experiments, whereas the best the law can do about judicial decisions is a sort of peer review, namely by way of an appeal to a higher court; and as a recent study in the journal Nature showed, peer review is not always a guarantee of accuracy.

FORENSICS and LAW in FOCUS @ CSIDDS | News and Trends

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This is a striking personal account recently given by an English legal gentleman before the Royal Society in London. His career spans formal scientific education, initial research experience, and a professional transition to the law. As of this writing he is President of the UK Supreme Court. He is Lord Neuberger.

These lecture notes are his verbatim account of the conceptual/philosophical voyage through the years and gives all of us a valuable view regarding scientific “binary thinking” contrasted with legal “logic” suppositions and moral proclamations.

Here is a quote of modest reflection:

” I believe that my scientific training has been valuable in my career in the law.”

And then he drops the bombshell:

“The explanation, I said, was plain: it is far easier to switch from a more rigorous subject to a less rigorous subject than the reverse.”

The “takeaways” will produce some insight.

Lord Neuberger (Long read)

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Reasoning about probability

There are many ways to approach the thorny issue of “reasonable doubt“.

Jury instructions may give guidance in this way:

“The State has the burden of proving the defendant guilty beyond a reasonable doubt. This means the State must prove each element of each charge beyond a reasonable doubt. In civil cases, it is only necessary to prove that a fact is more likely true than not or that its truth is highly probable. In criminal cases such as this, the State’s proof must be more powerful than that. It must be beyond a reasonable doubt. Proof beyond a reasonable doubt is proof that leaves you firmly convinced of the defendant’s guilt. There are very few things in this world that we know with absolute certainty, and in criminal cases the law does not require proof that overcomes every doubt. If, based on your consideration of the evidence, you are firmly convinced that the defendant is guilty of the crime charged, you must find her guilty. If, on the other hand, you think there is a real possibility that she is not guilty, you must give her the benefit of the doubt and find her not guilty.”

Estimates suggest that about 5% of people convicted and sentenced to death are innocent, meaning juries are regularly making mistakes, thinking a case for guilt has been proved beyond a reasonable doubt when this is not the case.

The reasons for these errors are undoubtedly complex and varied, but here I want to concentrate on fallacious reasoning about probability. Sometimes people talk about “too many coincidences”, when I hear that claim I immediately suspect fallacious reasoning.

How should a jury deliberate? Well, it would be good to reduce that error rate from 5% to a more acceptable rate, let’s say 1 in 1,000. That would be 500 times better than the current rate, and a significant improvement.

So let’s say we will convict if the chance of innocence is less than 0.1%, recognising that we cannot overcome every doubt. To put it another way, the probabilty of guilt should be more than 0.999.

But how can we estimate this probability in a rational way?

One thing to beware of is something known as the “prosecutors fallacy”.


At its heart the fallacy involves assuming that the prior probability of a random match is equal to the probability that the defendant is innocent. For instance, if a perpetrator is known to have the same blood type as a defendant and 10% of the population share that blood type, then to argue on that basis alone that the probability of the defendant being guilty is 90% makes the prosecutor’s fallacy (in a very simple form).

The basic fallacy results from misunderstanding conditional probability and neglecting the prior odds of a defendant being guilty before that evidence was introduced.

In other words, we must look at the “prior odds” of a defendant being guilty.

Let’s take a concrete example, the case of Jodi Arias. This may have looked like a simple case to a casual observer. Travis Alexander’s body was found dead in the shower at his home in June 2008. He had been shot in the head and stabbed repeatedly. Photographs recovered from a camera that was found in the washing machine showed Arias had visited Alexander on 4 June 2008, and pictures taken by the same camera showed Travis in the shower, around 5:30pm and then just a minute later, lying on the flood bleeding. Moreoever blood recovered from the scene contained a mixture of Arias’ DNA and Alexander’s DNA. However Arias when questioned first denied having visited Travis, then when shown the photographs claimed that intruders had appeared and shot and killed Alexander.

Finally she claimed that she had acted in self defence, that Alexander had become angry after she dropped his camera, and he had been shot after he assaulted her, then chased her, and she pointed a gun at him to keep him away ( explaining that she had squeezed the trigger without meaning to ). After he was shot, she claimed to be unable to remember very much about what happened, other than an overwhelming sense of fear.

The prosecution asserted that Arias’ account was untrue, and that Arias had travelled to Mesa with the intention of killing Alexander, evidenced by measures she took to keep the visit secret.

At first sight the defense case seems highly improbable. Why would Arias not have immediately told the police what happened if she acted in self defense? Why would Alexander become violent simply because she dropped his camera? And how if she was defending herself, could she have stabbed Alexander so many times, ultimately slashing his throat? And how could she have almost no memory of what happened after Alexander was shot?

Here there is a danger of what I would call a “lack of imagination”. The universe is full of events that are hard to comprehend, which may seem unusual, paradoxical and unlikely. For example, how did life start? Life is very complex, and it is hard to comprehend how such complex assemblies of atoms could come together by chance.

But we should also consider the prosecution version of events. The prosecution claimed that Arias had concealed her trip to Mesa, and there was circumstantial evidence to support this hypothesis. Travis was shot by a 0.25 caliber bullet, and  a 0.25 caliber gun had been stolen from Arias’ home seven days earlier. Secondly Arias had borrowed two gas cans from a friend, and bought a third gas can, and there was no record of her buying gas while in Arizona. Thirdly, Arias had turned off her mobile phone shortly before entering Arizona, perhaps in an effort to conceal the visit. Finally, when Arias was stopped by a policeman in Salt Lake City the day after Travis was killed, one of her licence plates was upside down, and the other was missing ( it was inside her car ). Could all this evidence of premeditated murder simply be a series of coincidences?

A reasonable person might easily conclude that this is overwhelming evidence of guilt. Firstly Arias’ denials, and secondly circumstances suggesting that she took measures to keep her visit to Mesa secret.

There is one big, massive problem here though. It can be expressed as a single word : why? Why would Arias want Alexander dead, and be prepared to risk ruining her life by being convicted of his murder?

In other words, the “prior odds” mentioned above are massively AGAINST Arias being guilty.

So, now to the question of how we could estimate the probability of guilt in the case, based only on the evidence given above.

There is no real doubt that Arias did kill Alexander. Firstly she testified that she killed him. Secondly her story that intruders appeared at the moment when Alexander was shot is not credible.

But is it possible that she was first attacked by Alexander? If there is a fight between two people, it’s reasonable to suggest that either could have started the fight, from that perspective, the chance that Arias is guilty is only 0.5.

The big issue here though is the improbability, before the evidence is considered, that Arias planned to murder Alexander. Planned murder is a very serious criminal offence, and very rare as well. Looking at women on death row in the United States, or the history of crime, there are almost no cases that could be said to be similar examples, where a woman has planned many days in advance to murder a man for no credible reason.

There was apparently no financial motive – although Arias did owe Alexander some money, it was not a large sum, and few people have even suggested that as a motive. Instead, the suggestion is that Arias may have acted due to feelings of jealousy or rejection. It is not unusual for men to murder women for this reason, especially at the end of a relationship. However cases of women murdering men for this reason seem much more unusual, and there seem to be no precedents for a woman who was not even living with the man at the time, and who had no reason to feel unreasonably rejected, to have embarked on murder.

From this perspective, the likelihood that Arias is guilty of murder planned a week or more ahead is very, very low, perhaps 1 in a million, or even 1 in a billion, perhaps even less, depending on your point of view.

So, the question then becomes, do the apparently improbable suspicious circumstances suggesting Arias concealed her trip to Mesa, combined with the apparent improbability of the defense case,  mean that it is very probable this is premeditated murder?

Let’s be generous to the prosecution here. Firstly, let’s say that the chance of such a suspicious event such as the theft of a gun of the correct caliber from Arias’s home a week before the murder is quite small. Perhaps 1 in 100. There is a problem here, in that the universe of possible “suspicious events” is very large. What if the theft had been two weeks before? That would presumably still be suspicious. What if the theft had been from the house next door, would that be suspicious? This consideration must tend to reduce the weight of this circumstance.

Now what about other circumstances? Well, I suggest that the other circumstances are really not at all conclusive. It is not unusual to switch a mobile phone off to save the battery. Paying for gas with cash is perhaps unusual ( which is what Arias claimed ). However having irregular license plates seems more likely to attract attention than be part of a plan of concealment, and the explanation Arias gave that pranksters were responsible seems more plausible to me.

So let’s take stock. Taking a view favorable to the defence:

Arias’ final story is in fact quite possible, with some imagination.

Likelihood that Arias planned the murder a week in advance for some very unusual reason : 1 in a billion.

Likelihood that the gun theft and other circumstances are just coincidences : 1 in a thousand.

Likelihood that Arias is guilty : only 1 in a thousand. Not nearly enough for a conviction.

Of course this process has been massively subjective. It is a matter of opinion how improbable the circumstances are, how improbable the defense case is, or how improbable it is that Arias is capable of premeditated murder planned a week in advance.

This is not the end of the matter though. There is a lot of evidence that has not yet been taken into account. The purpose of this article was to show the danger of believing the “too many coincidences” argument. We must not consider only circumstances that make the prosecution case seem likely, the general improbability of the prosecution case must also be taken into account.

I believe this is where juries mostly go wrong. There are numerous examples of defendants being convicted in spite of having a solid alibi. Many juries seem blind to exculpatory evidence or circumstances, and perhaps do not understand the idea of prior odds.

[ Please see here for a much more complete description of the evidence in this case ]

See also How juries are fooled by statistics a TED talk by Peter Donnelly.

Trapped with Ms. Arias

This blog is some observations about Kirk Nurmi’s performance as a lawyer for Jodi Arias, in light of some of the information he discloses about the pre-trial preparations in the first of three books about the case.

Although being a self-published book, presumably written without the aid of a professional editor, the first thing to say is I found the book to be very readable and engaging. Kirk explains his view of the law, the case and his feelings about Jodi Arias with great clarity. For anyone interested in the case, I would say this book is a “must-buy”.

I would also say this is a very honest book. It pulls no punches in making it very clear that Nurmi, before the trial began, did not like Jodi Arias and did not wish to represent her at trial.

There is a lot of fascinating information in the book, much of it new. For example we learn that the first domestic violence expert could not testify due to illness.

I have no criticism of the analysis Nurmi makes about the relationship between Jodi and Travis Alexander. I also agree with his assessment of the State’s professional witnesses. He observes that DeMarte was inexperienced, Flores was evasive, and suggests Dr Horn’s change of theory was suspicious. In addition Melendez was not a true expert, only having minimal training in the operation of Encase.

Now to some criticisms. I have to say Nurmi shows a lack of empathy. Of course an attorney must maintain some distance from his client, but by his own account he had a very poor relationship with both Jodi and her mother. He indicates he was unable to communicate effectively with Jodi at meetings, failing to adapt to any shortcomings she had.

He also jumps to early conclusions. For example he deduces from Jodi’s booking photo that she is mentally ill. According to my sources, the truth of the matter is that when the photo was taken, it was suggested to Jodi that she looked miserable, and so she smiled for the camera.

More seriously, he seems to assume that Jodi and not Travis was the aggressor in the fight that happened on June 4, 2008. I believe this mistaken belief meant that he did not closely examine the evidence at the scene to determine if it could be used to argue that Travis was in fact the aggressor.

He also failed to anticipate that the case would hinge on Jodi’s testimony concerning the gas cans, and failed to obtain evidence that would corroborate her testimony.

Ultimately I believe these failures contributed to Jodi’s wrongful conviction, but on the positive side, I also believe that the State’s case is utterly false, and Jodi should and will win a new trial.

I look forward to parts two and three.

Discussion here.

See also Raising the bar – but certainly not in Arizona by Lise LaSalle.




President’s Council of Advisors on Science and Technology Seeks Forensic Info

FORENSICS and LAW in FOCUS @ CSIDDS | News and Trends

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PCAST Forensic Science Questions

PCAST consists of 20 of the nation’s leading scientists and engineers, appointed by the President to provide direct advice to him and the White House on important matters of science and technology.

PCAST has recently begun to explore how best to ensure the quality of forensic science, based on reliable scientific principles and methods, within the criminal justice system.

PCAST members are interested in hearing from the broad stakeholder community on each of the questions listed below in an effort to better understand the landscape of this topic.

Please note that any comments are subject to public release under the Freedom of Information Act, and may be archived consistent with the Federal Records Act and Presidential Records Act, as applicable.

This form will accept submissions until Wednesday, December 23, 2015.

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UK : Police forced to reopen 350 cases botched by forensics officer who lied about credentials

FORENSICS and LAW in FOCUS @ CSIDDS | News and Trends

Stephen Beattie, a senior forensics officer, was suspended and then quit in 2011 after it emerged that he exaggerated his expertise

[This ethical transgression was first reported almost 5 years ago. Seems that this forensic review process described below was not a top priority.]

More than 350 police probes spanning 15 years were reopened after it emerged they had been botched by a senior forensics officer who lied about his qualifications.

Stephen Beattie worked for Staffordshire then Cleveland Police and told both he was a level two fire investigator.

But watchdog the IPCC found he had no academic qualifications in the field and exaggerated his expertise.

The cases reopened included 141 suspicious deaths and 214 arsons .

Beattie, 51, who was suspended and quit in 2011, inappropriately recorded his own opinion on how crimes occurred and did not handle items correctly.

Read more : Chief constable guilty of misconduct resigns amid political…

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My father, mental illness and the death penalty

Published on 9 Jun 2015

The story of Ricky, a convicted child molester and murderer, and the mother of the child he killed; and of mental illness, the death penalty, victimhood and seeking understanding.

Clive Stafford Smith OBE is a lawyer specialising in defending people accused of the most serious crimes, and is Founder and Director of the UK legal action charity Reprieve.

Clive spent 26 years working as an attorney in the Southern United States, where he represented over 300 prisoners facing the death penalty. Whilst only taking the cases of those who could not afford lawyers, he prevented in the death penalty in all but six cases (a 98% “victory” rate). Few lawyers ever take a case to the US Supreme Court. Clive has taken five, and all of the prisoners prevailed.

When The Shoe Shifts To The Other Foot

I think US prosecutors are far too keen to retry cases.

If a jury cannot reach agreement, then unless significant new evidence comes to light, proof that the defendant is guilty beyond a reasonable doubt seems unlikely.

I don’t know the evidence in this case.

Lawyers on Strike

So the very high profile prosecution of Pittsford’s Charlie Tan comes to an end in Justice Piampiano’s courtroom, not by a jury’s decision but by the judge’s.

The prosecutors are upset:

“This is appalling. In my 24 years, I’ve never in my life experienced anything like that. This whole trial presented a unique set of facts, but this is definitely unprecedented,” said District Attorney Sandra Doorley, R-Monroe County.

Prosecutor Bill Gargan interrupted the judge at one point. Piampiano told him to stop talking or he would have him handcuffed and thrown in jail. The two yelled back and forth several times as Gargan accused Piampiano of having amnesia – of forgetting some of the evidence that had been presented. Piampiano told Gargan he was offensive.

We at LoS were most impressed, however, by this comment:

“The judge’s decision did not comply with the law based upon the evidence presented,

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Sam Sheppard

A famous 3-ring circus trial from history, Edwards identified as the killer.

Wrongly Convicted Group Website

Samuel Holmes “Sam” Sheppard (December 29, 1923 – April 6, 1970) was an American osteopathic physician and, toward the end of his life, a professional wrestler. He was convicted of the brutal murder of his pregnant wife, Marilyn Reese Sheppard on July 4, 1954, at their Bay Village, Ohio, home. He spent almost a decade in prison, mostly at the Ohio Penitentiary, before a retrial was ordered, where he was acquitted in 1966.

On June 6, 1966, the U.S. Supreme Court, by an 8-to-1 vote, struck down the murder conviction. The decision noted, among other factors, that a “carnival atmosphere” had permeated the trial, and that the trial judge Edward J. Blythin, was clearly biased against Sheppard because Judge Blythin had refused to sequester the jury, did not order the jury to ignore and disregard media reports of the case, and when speaking to newspaper columnist Dorothy Kilgallen shortly before…

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