Firearms Analysis Flashcards
What is the definition of a firearm as per the Criminal Code?
A weapon from which any shot, bullet or other projectile can be discharged and that is capable of causing serious bodily injury or death to a person.
What must the Crown prove about firearms?
That the weapon IS a firearm
Does an expert need to be called when there is a certificate of analysis?
No.
What areas of firearms cases may experts need to be called?
Availability of parts to make the weapon operable as a firearm
Cartridge linking
What was the PCAST conclusion relating to firearms analysis?
Foundational validity: NO
Validity as applied: If admitted, must be reported with error rates and disclosure of expert proficiency testing results
What was the charge of interest (in class) in R. v. Donison?
Handgun with serial number removed found inside the radiator in the kitchen of an alleged stash house.
What was the overarching issue in R. v. Donison?
Did any of the 5 defendants possess the firearm?
What was the relevance of the expert evidence in R. v. Donison?
To show that firearm discharged was the same firearm seized from the alleged stash house.
What was the forensic expert called in for R. v. Donison qualified to give opinion evidence on?
Firearm cartridge linking
What was the opinion of the expert in R. v. Donison?
Both casings were fired from the same gun and it was identified within the limits of practical certainty.
What did the court agree upon with respect to Ms. Plath, the firearms expert in R. v. Donison?
Her opinion was subjective
No specific number of agreements between the two items for her to conclude a match
What was a limitation Ms. Plath discussed about firearm analysis in R. v. Donison?
There is no discipline-wide error rate and the existing validation studies only relate to particular models
What was the conclusion of the court in R. v. Donison?
Court not prepared to conclude a “match”
What did the court find in R. v. Creary?
Firearms expert evidence is admissible and reliable
The firearm Creary had and pointed at arresting officer is same gun used in shooting.
What was Ms. Plath’s opinion in R. v. Creary?
All 5 cartridges were fired by the same gun that fired the test round.
What was Ms. Plath’s statement of confidence in R. v. Creary?
Confident to a “practical certainty”
What did Ms. Plath acknowledge about her analysis in R. v. Creary?
There are both subjective and objective components
What was the verification process in Ms. Plath’s analysis in R. v. Creary?
Another qualified CFS scientist did a double-blind verification with same result.
What was the error rates discussed by Ms. Plath in R. v. Creary?
Not possible to assign one to work done at CFS.
But accuracy of scientific method has been validated through many studies, all between 0-2% error rates.
What was the opinion of the judge in R. v. Creary about Ms. Plath’s use of “within the limits of practical certainty”?
Not meaningless.
Absolute certainty is scientifically impossible and is not a legal standard.
Describe the differences in ideas of Ms. Plath’s proficiency testing in Creary vs Donison
Donison: no evidence she had undergone any, but she wasn’t asked
Creary: testified proficiency testing is part of CFS quality assurance program
What was the issues surrounding the use of PCAST by the judge in R. v. Donison?
Unsure how it came to be in front of the judge
Not an exhibit in the case
Ms. Plath was not questioned about it
What was the opinion of Ms. Plath in R. v. Hadi?
Three cartridge casings at the scene came from the same gun within the limits of practical certainty?
What was the opinion of the court as to Ms. Plath’s conclusions in R. v. Hadi?
Defence did not take issue with Plath’s conclusions
Court relied upon conclusions
What were the differences in R. v. Hadi vs Donison?
Testified about annual proficiency testing
Detailed evidence about error rates and validation studies
Qualifications of verifying scientist outlined
What did the judge in R. v. Hadi find different than the judge in R. v. Creary?
PCAST report not necessary to be submitted as evidence. Similar to recommendations of a commission of inquiry
Not binding but could be helpful to the court.
