Generally we cannot be sure of the truth, but have to make do with what is “probable”. The ultimate aim is to find two overall best hypotheses : one is the “defense case”, the other the “prosecution case”. There may be alternatives within such hypotheses. We then have to assess the probability of each hypothesis, taking all the evidence into account. We may use slightly “gray” logic, where evidence may be said to render a hypothesis “unlikely, but still possible”.
Hypothesis formation is important. Sometimes the most difficult part of figuring the truth out is finding the correct hypothesis, and not overlooking some possibility.
We have to watch out for false assumptions or inferences. Such a
All confessions are true
Nobody is ever framed
Documents are never forged
There are no random coincidences
Innocent people don’t lie
Police officers never lie
Police officers never plant evidence
People are rational – that is they do things which help themselves, they are “motivated”.
Experts never make mistakes.
Nevertheless, such assumptions/inferences are still normal when forming hypotheses to be tested and when evaluating hypotheses. We need to carefully consider especially whether actions are rational, and if they are not, whether the irrational “mistake” is reasonable or unreasonable, plausible or implausible.
If we call the prosecution hypothesis P and the defense hypothesis D, we will ultimately have one of the four possibilities below:
P is possible and D is possible => Not guilty, although we are not sure.
P is impossible and D is possible => Not guilty, we are sure.
P is possible and D is impossible => Guilty, we are sure.
P is impossible and D is impossible => Something is wrong. Either we missed a hypothesis, or made a false assumption/inference,
The rest of the article is examples to illustrate how this works, taken from cases I know well.
Examples of how hypothesis formation can be difficult
The difficulty of finding a correct hypothesis : this is difficult both for prosecutors and for innocent defendants. An example would be the Scott Peterson case when defense attorney Mark Geragos formulated a defense theory that was wrong, with regard to the time when Laci Peterson was abducted. He failed to take note of the time when Laci was seen walking the dog, and also the observations of the postman. It was also difficult to figure out the motive for why Laci might be abducted, or why someone would choose to frame Scott by planting the bodies near where he went fishing.
Often the process of forming a correct hypothesis is iterative, and the hypothesis has to be modified to take into account new evidence. Sometimes this may be difficult : for example, how should the apparent coincidence of a burglary in the Scott Peterson case be accounted for?
Examples of false assumptions / inferences
Point 1 : Numerous examples of false confessions exist. They are so common it is hardly necessary to give examples, but I will name Jeffrey Deskovic and Brendan Dassey.
Point 2 : Although cases where people are framed are not common, they do exist. Scott Peterson is such a case – the bodies of the two victims were planted in order to cast suspicion on Scott Peterson.
Point 3 : Edward Wayne Edwards forged numerous false documents, even going so far as to forge a fake birth date, five years later than his actual birth date.
Point 4 : Random coincidences do happen. For example Amanda Knox switched off her mobile phone on the evening that Meredith Kercher was murdered. It could be seen as suspicious, but there was a reasonable innocent explanation.
Point 5 : Innocent people do sometimes lie, sometimes because they think some circumstance ( such as an extra-marital affair ) will look bad, or because they are ashamed or think they may not be believed if they tell the truth ( Jodi Arias would be an example ).
Point 6 : Police officers do sometimes lie, an example would be the Debra Milke case.
Point 7 : Police officers do sometimes plant evidence, an example would be the Steven Avery case.
Point 8 : People sometimes act in an irrational way, especially when they are angry – perhaps because someone is not acting the way they want. An example would be Travis Alexander charging at Jodi Arias, even after she pointed a gun to keep him away. However if a hypothesis depends on a person acting in an irrational way, it’s likely wrong, especially if the irrational behaviour is over a long period of time.
Point 9 : “Junk science” ( experts making mistakes ) is very common. One example is the case of David Camm where experts testified blood spatter had to be from a gunshot when that was not the case.
The problem seems to be that many jurors just do not have a proper conception and understanding of proof, and appeal courts show extreme deference to the judgement of jurors. So somebody can be convicted of murder based entirely on speculation rather than proof.
One sign is a trial of extreme length. That happens when there is no proof and it’s all guesswork what really happened, or worse it’s clear a person is innocent but they are still found guilty.
There is also evidence that jurors who are in favour of the death penalty are precisely those jurors who will convict when evidence of guilt is lacking, so the death penalty compounds the problem.
In a criminal trial, the prosecution may offer circumstantial evidence which is less than conclusive, and suggest that an innocent explanation is unlikely, even though an innocent explanation is quite reasonable, and is not excluded by reliable evidence
People sometimes say “I don’t believe in coincidences”. The universe of potential suspicious circumstances may be very large, and we often cannot even say if a coincidence is likely or unlikely.
“As with deductive arguments, biases can distort the proper application of inductive argument, thereby preventing the reasoner from forming the most logical conclusion based on the clues. Examples of these biases include the availability heuristic, confirmation bias, and the predictable-world bias.”
Confirmation bias may set in when inductive arguments are made (whether implicitly as evidence is presented, or explicitly in closing arguments), and evidence that shows the prosecution case is improbable may be ignored as a result of confirmation bias.
I believe wrongful convictions can easily occur when ambiguous evidence is presented. It is quite natural for jurors to reason inductively, as inductive reasoning often produces good results, even though it is not reliable.
A question that often occurs to me is this : can many different “suspicious” facts be combined to arrive at proof beyond a reasonable doubt?
My answer would be “Yes”, but it can be very dangerous, and can easily lead to wrongful convictions.
The reason I say yes, is that DNA evidence actually does just that. DNA is sampled at many different locations, each individual location is only weak evidence, when combined together, strong identification evidence is produced.
It’s impossible to be certain about almost anything. You will have wrongful convictions in any system of justice, because occasionally circumstantial evidence will lead you astray.
However, if you are going to convict on weak circumstantial evidence ( say coincidences that might be random), I would say it’s very important to check first whether there is evidence the OTHER way ( evidence inconsistent with the prosecution case ).
Some examples would be:
Lack of motive,
Facts that don’t fit,
Things that don’t make sense
Contradictions and Inconsistencies
Disagreements, battling experts.
These should all be red flags that create reasonable doubt in the mind of a juror.
Distressingly, jurors quite often fail to notice the red flags, resulting in a wrongful conviction.
See also Broken on the Wheel “Voltaire became steeped in the country’s rules of criminal procedure, a labyrinth he found appalling”
The evidence was mostly rubbish – but there was a lot of the rubbish, and in France at the time, even evidence deemed “half-complete” or “imperfect” could convict, by adding fractions of a proof to make a whole.
Over many centuries, women have been put on trial, accused of “witch-craft“, or in more recent times of being a “Femme Fatale” – having the ability to control men and to commit heinous crimes for no plausible reason. Debra Milke has spent 23 years on death row in Arizona. On the flimsiest evidence, people are still readily convinced that an instance of this elusive woman has been found. A woman who leads a blameless life, but then one day turns into a savage, calculating murderer for no good reason. The evidence is just some vague suspicion : the actual killer makes a suggestion, not repeated in court. A burglary with nothing taken, a gun is stolen.
Let’s be clear : “Femme Fatale” is simply the modern word for “Witch”. It serves to make discussion more plausible, but no less irrational. How many billions of women have lived on the planet? Not one “Femme Fatale” or “Witch” has ever been identified with certainty. It is extraordinary that the myth lives on. Harry Potter is fiction not fact. Every child knows this.
In a witch-hunt trial, the prosecution focus on tiny details, remote from the scene of the crime – a missing mark on a receipt, a telephone call placed at an odd hour, a mobile phone switched off, a mobile phone switched on. These tiny signs are interpreted as evidence of the accused’s guilt. If something does not fit, it is because the accused has cunningly manipulated or cleaned the crime scene, with infinite foresight.The accused is cunning and intelligent one moment, but makes stupid mistakes the next. A single phrase is picked out from thousands of pages of writing, taken out of context. If no mark can be found, an expert is brought in to find what is not there using some contaminated source. Detectives and Doctors are called by the prosecution to give any testimony that is needed.
No expense is spared. When evidence is disproven, a search for fresh evidence is conducted. Above all, the witch is required to prove her innocence beyond every doubt, an impossible task. She is thought to be a great liar, somehow she has an answer to everything, but every explanation is deemed to be pure invention. A hundred reasons for suspicion are laid against her, if a single one cannot be innocently explained, in that instant, she is doomed. The more she struggles, the more she explains, the more scorn is placed on her efforts, the more she incriminates herself in the mind of the mob. The burden of proof is reversed, the woman is guilty unless she can prove herself innocent. A succession of trials may be held. The general public become prejudiced, because they only have to believe in one bogus piece of evidence to become convinced of guilt, and often the innocent explanation is never heard – suppressed in the general condemnation “why would anyone want to defend this woman”.
The demeanour of the accused is confirmation, looking into the eyes allows a diagnosis to be made. If she cries, these are tears of self-pity, guilt, or an act. If she doesn’t cry, she is cold-hearted. These gentle women are often described as frightened rabbits, caught in the headlights of a rampaging lynch mob. No mercy is to be shown, the lack of a criminal record counts for nothing. The mob insists on the maximum penalty available – solitary confinement, life imprisonment with no parole, execution. Some even call for the woman to be executed then brought back to life, to be killed again and again, subjected to every imaginable torture.
In fact these cases can and should be easily resolved by simply checking that the woman is non-violent and gentle with no criminal record. That should be sufficient proof of innocence. It cannot be stressed too much – a woman of this type does not, cannot, never has and never will commit heinous murder for some implausible reason, such as “freedom from parental responsibility”, “revenge” or “jealousy”. If a woman of this type is alleged to have killed someone, it is either an accident, self-defense or simply not true, it is never murder.
The witch-hunters are quite sincere in their mistaken beliefs. They are consumed by the fear that the accused might escape punishment, even as they are aware of her charming appearance. I believe it is some kind of psychological imbalance – they know they must not be influenced by the pretty girl, but over-compensate, and ignore the obvious evidence in front of them. They genuinely do not want to believe, but they feel it is some civic or religious duty, and they really do believe. They are locked into a state of confirmation bias, oblivious to the lack of decisive evidence.
Any witness who might support the accused is attacked, threatened with death, perjury and slander charges, until nobody will testify for her out of fear. Anything can be twisted, because the end justifies the means, her guilt is never doubted.That is the tragedy. Once can forgive the family of the person who has died, grief clouds judgement. But people who administer justice should know better. In the internet age, the odds against the accused are even more staggering, with social media used to manipulate thousands of dedicated haters in an instant.
All the parties are losers – especially the accusing family, their faces twisted with mistaken hate, as they dedicate their lives to the futile hunt, refusing to even hear the accused. The prosecutor storms and rants, displaying any gruesome photographs available. He argues maybe this, perhaps that. The jury is cowed into the fear of error, openly weeping with horror, confusion, stress and exhaustion as they reach their verdict. Even the judge may weep openly in court, her face twisted with conflict, convinced of the witch’s guilt, but determined not to allow any avenue of escape.
You may not believe that the search for the Femme Fatale is still pursued using Witch-hunts in the Western world, but consider the following quotes:
“We knew she was guilty of murder without physical evidence.” Edgardo Giobbi, Investigator, November 2007.
“Raffaele Sollecito had probably given her that knife for reasons of self-defense, a knife which she could transport in her capacious purse.” Motivations report, Giancarlo Massei, March 2010.
“She was a diabolical, satanic, demonic she-devil. She was muddy on the outside and dirty on the inside. She has two souls, the clean one you see before you and the other.”Carlo Pacelli, September, 2011.
“The word “probable” (or “improbable”) occurs some 39 times in the course of the motivation.” Presiding Judge Dr. Hellman, Motivation report, December 2011.
“I really hate to be saying that she is guilty but sadly, she is as guilty as it gets.” Donald Trump, May 3, 2013.
“Alyce LaViolette, she had a motive to lie. I mean, um, maybe perhaps it was her reputation that she was interested in, or things like that.” Juan Martinez, closing argument, May 3, 2013.
“If you believe what the defendant is telling you, then all of these arguments then do begin to make sense.” Juan Martinez, closing rebuttal, May 4, 2013.
“I don’t have all the information, but I think she’s guilty.” Governor of Arizona, Jan Brewer, May 7, 2013.
“God gives us big warning signs that something is very wrong with people. That witchcraft thing was it.” – Nancy Grace
On 8th May 2013, Jodi Arias was found guilty of premeditated first degree murder. The jury was not sequestered.The televised show trial broadcast nightly to millions of Americans was nothing less than pornography, thrilling the audience with the possible execution of an innocent Christian woman, the modern day version of the Christian martyrs slaughtered in the Colosseum. There was no attempt at fair, balanced coverage, the defense case was never fairly discussed in the live coverage. Cheerleaders for the prosecution were feted, the occasional supporter was mocked mercilessly, after showing just a few hand-picked seconds, while jurors followed the public mood on twitter in the jury room.