Tutorial Notes
These notes are an abridged and extended version of David Field’s comments.
1 Michelle suffered several deep stab wounds to various parts of her body, any one of which could have been the fatal one.
• This statement is relevant to how Michelle died;
• This statement is also admissible, even though it is Dr Paxton’s opinion, because he is an expert in his area and his statement therefore satisfies the opinion rule;
• This statement is likely to carry considerable weight with the jury because of Dr Paxton’s expertise and experience.
Extract from ‘Admissibility of expert opinion Evidence’ by Martin Sides Q.C.
Definition of the word ‘opinion’: “an inference from observed and communicable data” or facts (Australian Law Reform Commission Report 26, para 156; Cross – para 15.3).
It is generally accepted that a witness is only permitted to speak of what he or she directly
observes through the use of the five senses. The drawing of inferences is the function of the tribunal of fact. It is not the business of witness’ to draw inferences or express opinions, a witness’ function is to state facts.
The dividing line between “fact” and “opinion” is far from clear and the above rules are
The Essay on The Fact Statement of Alcoholism
The above mentioned students were scheduled for grievance hearing together with their parents in the grievance office last October 19, 2012 at 2:00 PM. Mrs. Buenaflor our presiding chairman introduced the committee members. Mr. Bobiles started the questioning to Bai Rachma Carnain. When asked what kind of liquor did she bring and how many milliliters. Bai Rachma brought one can of San Miguel ...
not necessarily easy in their application. For the purposes of this paper, it is unnecessary
to explore those murky waters because there is a well established exception that permits an “expert witness” to give opinion evidence. Before such an opinion is admissible, three
things need to be established:
(i) the field of expertise;
(ii) the witness is a qualified expert; and
(iii) the matter to which the material relates is not within ordinary human
experience – “common knowledge”.
2 Several of the wounds, because of their location, could not have been inflicted by Michelle on herself, and the number and ferocity of the wounds greatly reduce the possibility of suicide.
There is more than one statement here, and the statements must be carefully distinguished.
• The location of the wounds is a matter of simple observation, and could, for example, have been testified to by a police officer who attended the crime scene or the post-mortem. It is relevant and admissible without reference to the opinion rule, although an expert in anatomy would be required to draw the conclusion such wounds could not be self-inflicted, but relies for its relevance on the additional fact that Troy, on his own admission, was the only person present. Taken along with this and other factors it is likely to carry considerable weight in the jury’s final deliberations.
• The number and ferocity of the wounds are being used as the factual basis for a further opinion by Dr Paxton to the effect that the death was not suicidal. It is clearly relevant to the ultimate issue of whose actions caused Michelle’s death, but may not be admissible if the Defence can argue successfully that Dr Paxton has over-stepped the area of his expertise and is now offering an inadmissible opinion which would better be given by a psychiatrist. Even if it is ruled admissible, the weight to be attached to it by the jury will depend on how successfully the Defence can attack Dr Paxton’s experience and expertise in suicide deaths.
Extract from definition of ‘weight of evidence’ in the Free Dictionary:
The weight of evidence is based on the believability or persuasiveness of evidence. The probative value (tending to convince a person of the truth of some proposition) of evidence does not necessarily turn on the number of witnesses called, but rather the persuasiveness of their testimony. For example, a witness may give uncorroborated but apparently honest and sincere testimony that commands belief, even though several witnesses of apparent respectability may contradict her. The question for the jury is not which side has more witnesses, but what testimony they believe.
The Essay on Jury Trial Analysis
Jury trial refers to a legal proceeding, whereby a panel of adjudicators makes decisions that are put into practice by the judges. A jury decides upon dubious issues of fact that can either be in a criminal or civil trial. It is a constitutional right for those charged with criminal and civil offenses to face trial by jury. However, in civil trials the defender and the offender can have a ...
Particular evidence has different weight in inducing belief with respect to the facts and circumstances to be proved. Evidence that is indefinite, vague, or improbable will be given less weight than evidence that is direct and unrefuted. For example, a criminal defendant’s testimony that he had never been at the scene of a crime would be given little weight if his fingerprints were found at the crime scene and witnesses testify they saw him at the scene. Similarly, evidence given by a witness who testifies from personal observation is of greater weight than evidence offered by a witness who is testifying from general knowledge alone.
3 Michelle was two months pregnant.
Clearly potentially admissible given Dr Paxton’s expertise, but is it relevant? To assess this as being relevant as a possible motive for murder assumes Troy was unhappy with Michelle’s pregnancy. Given that a jury member may draw the same inference, Troy’s counsel will attack the relevance of Michelle’s pregnancy on the basis that it is ‘neutral’ as to her cause of death and argue that its admissibility may have a tendency to mislead the jury and prejudice Troy (probative value outweighed by prejudicial effect).
However, the statement’s very neutrality is a counter argument to the defence’s claim it should not be admitted. On the likely assumption that it will be admitted, Troy’s counsel will try to minimise the jury’s assessment of its weight. This is known as the tactical burden. One way to achieve this is to have Troy give evidence that either he knew nothing of the pregnancy or that he was happy at the prospect of fatherhood. The former reduces the weight and the latter detracts from the likelihood that Troy killed his pregnant wife. Of course, once Troy takes the stand, the Crown can cross-examine him with all the attendant risks that the jury will conclude he is lying on this issue.
The Essay on Collecting DNA Evidence
For many years, fingerprints were the gold standard for linking suspects to a crime scene. Today, the gold standard is DNA evidence because DNA can be collected from virtually anywhere. Even a criminal wearing gloves may unwittingly leave behind trace amounts of biological material. It could be a hair, saliva, blood, semen, skin, sweat, mucus or earwax. All it takes is a few cells to obtain enough ...
4 DNA taken from the foetus could not be linked to Troy.
Troy’s defence counsel will likely challenge the admissibility of conclusions drawn from DNA analysis by a pathologist on the grounds this is outside Dr Paxton’s area of expertise. DNA is a specialised area of forensic science. Dr Paxton can give evidence he extracted a sample of foetal tissue, but the relevance of this to the eventual result will depend on the evidence of experts in the field. The Crown will be aware of the need to join up the dots for the jury and will likely have the necessary witnesses to link all the testimony together. The Crown will need to ensure that the foetal tissue sample extracted by Dr Paxton was the same sample examined by the DNA expert.
Assuming the Crown gets in the DNA evidence, then the defence can attempt to minimise the weight given to this evidence by Troy testifying he knew he was not the father but was untroubled by this outcome.
Extract from Human Genome Project Information
How does forensic identification work?
Any type of organism can be identified by examination of DNA sequences unique to that species. Identifying individuals within a species is less precise at this time, although when DNA sequencing technologies progress farther, direct comparison of very large DNA segments, and possibly even whole genomes, will become feasible and practical and will allow precise individual identification.
To identify individuals, forensic scientists scan 13 DNA regions, or loci, that vary from person to person and use the data to create a DNA profile of that individual (sometimes called a DNA fingerprint).
There is an extremely small chance that another person has the same DNA profile for a particular set of 13 regions.
Some Examples of DNA Uses for Forensic Identification
• Identify potential suspects whose DNA may match evidence left at crime scenes
• Exonerate persons wrongly accused of crimes
• Identify crime and catastrophe victims
• Establish paternity and other family relationships
5 The textbooks he has read have informed Dr Paxton that sexual jealousy is likely to provoke extreme anger in a young male and has in many cases in the past led to savage attacks on sexual partners by jealous husbands and boyfriends. He is ‘satisfied’ that this is how Michelle came to die at Troy’s hands.
The Term Paper on Expert Witness Testimony
Ethics are very significant in testimonies given by expert witnesses. The American Bar Association (ABA) had not introduced enforceable system regarding ethics and the way attorneys ought to maintain good behaviors until 1908 (Dror, Kassin, and Kukueka, 2013). The organization later introduced several ethics that have been the main source of direction concerning judicial and lawyer ethics. ...
There is little doubt that Dr Paxton has stepped out of his area of expertise into the preserve of a forensic psychiatrist. However, given the potential relevance to the question why Troy might have killed Michelle, there is a danger if admitted the jury might be tempted to attach too much weight to the statement. If Troy was convicted, this would be an obvious appeal point. Even if the appellate court upheld the appeal point, there is a possibility that the court would apply the ‘proviso’ that no substantial miscarriage of justice has occurred.
Abstract from ‘The Proviso in Criminal Appeals’ by Catherine Penhallurick
The ‘proviso’ enables a court hearing a criminal appeal to dismiss the appeal if it accepts that, although there has been some fibrin of error in the trial, there was no ‘substantial miscarriage of justice’. The existence of the proviso reflects the need to balance an accused person’s right to a fair trial, conducted according to law, with the desire to avoid overturning convictions on the basis of inconsequential errors at trial.
R v Marquard
R. v. Marquard [1993] 4 S.C.R. 223, is a leading case of the Supreme Court of Canada on the admissibility of expert testimony.
Debra Marquard was charged with aggravated assault for allegedly placing her 3 year old grand-daughter’s face on a hot stove as punishment. At trial Marquard had claimed that the girl was burnt while playing with a butane lighter.
During the trial the court heard testimony from Dr. Mian, an expert on child abuse, regarding the burns to the child despite having no medical expertise on burns.
At issue on appeal was the trial judge’s warning of the frailty of the child’s testimony and the ability of an expert to give opinion evidence on matters outside their area of expertise.
McLachlin J observed that where a witness has “not shown to have possessed expertise to testify in the area, his or her evidence must be disregarded and the jury so instructed”. An expert going beyond their ability should not be given any value. The Court must be satisfied that the expert is qualified in all matters to which he or she will answer questions.
The Term Paper on Court of Appeals of Ohio,First District, Hamilton County
On a morning in early December 1993, plaintiff-appellant Paul Nadel was driving his son, plaintiff-appellant Christopher, and two younger daughters, Ashley and Brittany, to school.1 Paul’s mother, plaintiff-appellant Evelyn Nadel, was seated next to the passenger window. Christopher was seated in the front seat between Evelyn and Paul, with one foot on the transmission hump and one foot ...
Despite the opinions given on the child’s burns being outside of the doctors’ expertise, it was admitted as they had at least some degree of knowledge. McLachlin stated:
The only requirement for the admission of expert opinion is that the “expert witness possesses special knowledge and experience going beyond that of the trier of fact”: R. v. Béland, [1987] 2 S.C.R. 398, at p. 415. Deficiencies in the expertise go to weight, not admissibility.
The opposing counsel will always have the ability to object to any opinions given that go beyond expertise.
