Expert Witness Roles And Duties Flashcards
When is expert witness admissible
Where issues in dispute involve matter so specialist or technical that that are deemed to go beyond the every day knowledge of judge or jury
Expert witnesses may give their opinion of the facts proven in courts but they should not
Usurp the responsibility of the fact finder by giving their opinion on how the court should assess what its had heard
Kenny
V
Cordia
4 criteria for admissibility of expert evidence
- evidence must be helpful
- expert must have necessary knowledge and experience
- witness must be impartial in their presentation and assessment of evidence
- must be a reliable body of knowledge or experience to underpin evidence
Davie
V
Magistrates of Edinburgh
Role of witness is not to definitively decide case, even where giving evidence on crucial point
“Expert witnesses, however skilled can give no more than evidence. They cannot usurp the function of the jury or judge.. their duty is to furnish them with the necessary scientific criteria for testing the accuracy of their conclusion so as to enable them to form their own independent judgement”
Mitchell
V
HMA
Role of witness not to decide case
Police officer asked for assessment of situation in drugs case
Held to be asking him to comment on ultimate issue at hand.
Not within role of expert and thus not allowed
Ingram
V
Macari
Witness may not express opinion which usurps function of the court
Appeal debated in fact that expert witness in case had applied a legal test reserved for the court when they gave opinion that magazine not likely to corrupt morals of readers
Must only provide info to help court reason and decide
The ikarian reefer
Duties of expert witness
7
Independent and uninfluenced by the urgency of litigation
Independent and unbiased assistance to court
Facts or assumptions to be stated
Should make clear when particular question calls outside expertise
If opinion not properly researched due to insufficient data, make clear provisional opinion
I’d report is not whole truth should qualify it
If change of view after hearing other evidence should be made clear without delay
Facts detracting from opinion are not to be omitted
Ikarian duties applies in
Mctear v imperial tobacco
Held that less weight was to be afforded to expert witness evidence as they had engaged in advocacy
This contravened the duty of expert to provide unbiased and independent views
R
V
Harris
Established that an expert is under a duty to set out a full range of opinion, including any contrary opinion
Eg if aware of any counter arguments to what they are saying, must disclose this
Hainey
V
HMA
Where witness speaks to evidence which is out of their area of expertise the evidence can be irrelevant
Murder of baby case, issue being cause of death, natural or not?
Forensic anthropologists gave evidence which during they commented upon issues regarding Harris lines which was an area they weren’t experts. Judge didn’t tell jury to disregard.
Held: material misdirection and mistrial. Conviction for murder quashed.
Gage
V
HMA
Where expert evidence is not deemed necessary, it will be deemed inadmissible.
Drive by shooting case. Wanted to reopen case and lead fresh evidence from expert in eyewitness identification. Processes followed were suggestive.
Held: did not meet test of necessity, the issue of suggestibility was not our with the knowledge and experience of ordinary jurors and was therefore not needed.
Hodgson
V
HMA
Necessity of expert evidence
Rape case, 17 year old with learning difficulties. Meant wasn’t able to understand sexual natures properly
Difficulties would result in evidence appearing odd to jury unless explained by expert
Expert necessary to give evidence in understandable way
