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Annual Inspections Done Without Reference to Manufacturer's Specifications

May 16, 2018
8 min

Annual Inspections Done Without Reference to Manufacturer's Specifications

This is a sample cross-examination of an Ontario CFS scientist on the procedure used to perform an initial factory calibration (or a subsequent re-calibration by the factory) of an individual Intoxilyzer 8000C. Purposes of this cross-examination: [respecting type approval by the Alcohol Test Committee and Minister of Justice] To confirm that when new instruments are being evaluated, various solutions are used between 50 and 400 mg/100mls. To confirm that when new instruments

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Change at One Point but Not at Another Point that is Equivalent

Apr 13, 2018
5 min

Change at One Point but Not at Another Point that is Equivalent

This is a sample excerpt from a cross-examination of a Crown expert using data from periodic inspection of an approved instrument. The multiple-point control test data from an annual periodic inspection in Ontario or from a re-calibration as in Vallentgoed can be very useful to the defence in cross-examing a breath tech or a Crown expert to identify drift in accuracy and precision over time. Purpose: To suggest that there is empirical evidence in the matter before the Court o

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Start By Defining "Reliability" don't focus on "Accuracy"

Apr 6, 2018
6 min

Start By Defining "Reliability" don't focus on "Accuracy"

Purpose: To remind the Court, "thing 1" in 258(1)(c) is unconstitutional under Charter 11(d) (R v St-Onge) but is saved by section 1. To remind the Court that 258(1)(c) is saved by section 1 because of Parliament's purpose which is weight consistent with scientific reliability. To demonstrate to the Court that the SCC in St-Onge relied on the paper by Brian Hodgson. To bring that paper before the Court and make it an exhibit. To ask the government scientist to concede the def

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Response Drifts Over Time

Mar 23, 2018
3 min

Response Drifts Over Time

In an article relied upon by the SCC in St. Onge, Brian Hodgson stated: Defence lawyers need to educate themselves about the meanings of "drift" and "over time". What is it that actually "drifts"? What happens "over time". Are these concepts important to clarify during any cross-examination of a Crown expert? Can the reality of drift over time be satisfied by single point control tests? Is more required to maintain reliability over time? The ATC and CFS regularly opine that a

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How to Calibrate - Teach an AI - Build the Inverse Logarithmic Calibration Curve

Feb 28, 2018
3 min

How to Calibrate - Teach an AI - Build the Inverse Logarithmic Calibration Curve

Purpose: To educate the Court about the Analytical Theory of the 8000C Optical Bench including Emitter, Sample Chamber, Dual Detectors, Inverse Logarithmic relationship, and building the Calibration Curve based on the theory that differing ethanol concentrations have differing % absorption of IR light. To lay the groundwork for the importance of calibration and re-calibration respecting the reliability of any approved instrument. To explain the auto-calibration function of th

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Uncertainty of Measurement for Lawyers and Judges

Feb 4, 2018
5 min

Uncertainty of Measurement for Lawyers and Judges

Lawyers and Judges need to get past their deep-seated fear of uncertainty. If we are to promote the use of good science, in Court, we, as lawyers, need to stop thinking in terms of absolute certainty in science. We are used to the concepts of "guilt beyond a reasonable doubt" and "on a balance of probabilities", why can't we attempt to wrap our heads around probability and uncertainty of a measurement result in the qunatitative analysis discussed every day in Court? Isn't it

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Feb 1, 2018
1 min

Periodic Inspection Must Be Done Under Stable Lab Conditions

Purpose: To challenge the CFS expert's position that inconvenient data should be excluded for the purpose of calculating precision. To obtain an admission that the local police service is not properly assessing accuracy and precision during periodic inspections because they are not assessing under stable conditions. To illustrate the importance of an O'Connor order requiring production of officer's contemporaneous documentation at the time of the inconvenient data to determin

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Police Services Use Control Test Data Outside MPE to Calculate Precision

Jan 31, 2018
5 min

Police Services Use Control Test Data Outside MPE to Calculate Precision

Purpose: To obtain an acknowledgement from a CFS scientist that even though he would exclude data outside (the Maximum Permissible Error in Ontario) 90 to 110, in calculating precision, at least one police service in Ontario is using data outside 90 to 110 in calculations of precision during periodic inspection. The point is that even though the Crown's expert has opined that data (at 34.0 +/- .2 C) outside the +/- 10 mg/100mls acceptable values should be excluded from any c

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Ignoring Inconvenient Data in Calculation of Precision

Jan 30, 2018
5 min

Ignoring Inconvenient Data in Calculation of Precision

Purposes of this cross-examination: To challenge the opinion that data outside maximum permissible error (outside +/- 10 mg%) should be excluded from any calculation of precision. The cross-examiner should have called evidence in reply from a statistician or other expert in outliers. Note: The cross-examiner and the Crown expert had vastly different perceptions of what data could be used to calculate precision/standard deviation. The defence was suggesting that if you use al

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Defence Methodology Calculating Precision in the Field

Jan 29, 2018
6 min

Defence Methodology Calculating Precision in the Field

Purpose: To establish a better methodology for calculating precision of an approved instrument in service. To apply CFS methodology using control checks re calculation of uncertainty of measurement in blood/urine analysis to evidentiary breath testing. (Please note that these examples are provided for the purpose of education and discussion among defence lawyers and experts only, these images should not be reproduced. No attempt should be made to use them in Court. The origin

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Precision Testing Using Only 2 Data Points is Inadequate to Calculate Precision

Jan 28, 2018
5 min

Precision Testing Using Only 2 Data Points is Inadequate to Calculate Precision

Purpose: To elicit evidence to the Court as to the inadequacy of calculation of the instrument's precision by the local police service, close in time to the subject tests. To obtain admissions from the CFS expert as to proper methods for calculating precision. To confirm Mr. Kupferschmidt's evidence that the local police had stopped doing linearity checks by the time of this periodic inspection. Q. ..... If we go back and we count back 50 control tests. A. Yes. Q. Prior to

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Government Scientists Calculate Uncertainty of Measurement - Why Can't We?

Jan 27, 2018
9 min

Government Scientists Calculate Uncertainty of Measurement - Why Can't We?

Purpose: To obtain admissions about the use of historical control test data by the Centre of Forensic Sciences in Toronto to calculate standard deviation and uncertainty of measurement. To obtain an admission that the same approach could be used with historical data of Intoxilyzer control tests to prepare statistical data of accuracy and precision at different points in time so as to assess drift in accuracy and precision over time, in other words, reliability. Q. Let’s – let

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Checking Analytical Variability and Accuracy of the Instrument? Where?

Jan 24, 2018
4 min

Checking Analytical Variability and Accuracy of the Instrument? Where?

Purpose: To explore the lack of a lab setting when accuracy and precision of the instrument are checked on periodic or annual inspection. To explore the lack of Standard Operating Procedures when accuracy and precision of the instrument are checked on periodic or annual inspection. Q. I see. All right. A. Now, if you wanted to look at the analytical variability and accuracy of the instrument. Q. Yes. A. Then you would have to go look at these here on page 43 of Exhibit 1

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Distorted Concept of "Accuracy", "Precision", and "Reliability"

Jan 22, 2018
6 min

Distorted Concept of "Accuracy", "Precision", and "Reliability"

Purpose: To remind the Court of the concept of "reliability" used by the SCC in St-Onge. To educate the Court as to the definitions of "accuracy", "precision", and "reliability" used by Brian Hodgson in his paper relied on by the SCC in St-Onge. To focus on drift in accuracy and precision over time from: the manufacturer's specifications, and/or the accuracy and precision of the 8000 that was evaluated, and/or this specific instrument when first placed into service, as compar

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Jan 21, 2018
1 min

Attempt to Distinguish from Jackson and Vallentgoed

Purpose: To support argument that the Maintenance History shows that the instrument was taken "out of service", for "consistently low cal. checks" and as a result "requires calibration". Can the matter not be distinguished from Vallentgoed where the maintenance log revealed that the instrument was taken out of service for routine maintenance and periodic re-calibration? To support argument that the Maintenance History reveals that the instrument was taken out of service for a

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No Sampling of Aging Instruments in the Field

Jan 19, 2018
5 min

No Sampling of Aging Instruments in the Field

Purpose: To suggest that ATC/CFS scientists cannot provide any scientific opinion of the reliability of aging instruments out in the field without conducting an empirical study of instruments sampled from the field. To suggest that ATC/CFS scientists have no idea whether or not instruments in the field are performing in accordance with manufacturer's specifications. To identify the lack of any system of "verification" in Canada that instruments in the field are performing in

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Manipulating Control Test Data to Enhance Precision

Jan 15, 2018
6 min

Manipulating Control Test Data to Enhance Precision

Purpose: To neutralize the government scientist's assertion that anomalous data should be excluded from calculation of precision. To obtain an acknowledgment of drift in precision over time (see Hodgson definition of reliability) To challenge the propriety of throwing out control test data outside 90 - 100 mg/100mls in any calculation of precision This cross-examination shows the need for defence counsel to retain experts in statistics AND metrology. This cross-examination sh

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Error Rates and Drift in Precision

Jan 14, 2018
7 min

Error Rates and Drift in Precision

Purpose: To establish that the ATC/CFS is not sampling from aging instruments out in the field to determine error rates To establish that the ATC/CFS is not allowing for drift in precision of instruments as they age without re-calibration To suggest possible acceptable or normal error rates Sample cross-examination of a CFS expert on an instrument that has an error rate of 22% in the 50 cal. checks prior to the subject tests Q. Now, I just want to go back to the question of

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