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Canada's NRC on Traceability

Mar 26, 2018
5 min

Canada's NRC on Traceability

Defence lawyers need to convince the criminal justice system that "traceability" of all forensic measurements is a condition precedent to reliability. What does "traceability" mean and is it part of Canadian criminal law? What does the Canadian scientific community have to say about "traceability"? Why is the establishment of "calibration intervals" required to maintain "traceabilty"? Are "étalon" and "norme" the same thing? Are these concepts easier to understand in French?

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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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8000C Auto-Calibration Sequence - How to Run the Auto-Calibration Sequence

Mar 1, 2018
6 min

8000C Auto-Calibration Sequence - How to Run the Auto-Calibration Sequence

Purpose of this cross-examination: To educate the Court about the calibration sequence run on the approved instrument at the factory. To obtain an admission from the Crown expert that without the proper auto-calibration AND creation of a unique calibration curve, the instrument is not reliable. Every individual instrument has a unique calibration curve. Every individual re-calibration at the factory or at the factory-authorized Canadian service centre produces a unique calibr

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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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Calibration Laboratory Requires Accreditation

Feb 26, 2018
2 min

Calibration Laboratory Requires Accreditation

Purposes: To obtain an admission that calibration or re-calibration needs to be done by an entity that is accredited by ASCLD/LAB ANLAB to ISO 17025 standards. To obtain an admission that the local police service or local service centre which has conducted a re-calibration does not have such accreditation. The cross-examiner should have gone further on this issue to expand this line of questioning to Mega-Tech, Davtech, and GCS Technical Services. Sample cross-examination of

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AI Hardware and Software Can't Measure Without Learning and Re-Learning

Feb 25, 2018
6 min

AI Hardware and Software Can't Measure Without Learning and Re-Learning

Purpose: To educate the Court as to the "why" of the unreliability of an approved instrument to measure across the measuring interval if it has not been recently calibrated, inspected, maintained, re-calibrated. It seems strange to think that a modern "approved instrument" has to "learn" - that it has a kind of artificial intelligence. In reality it's true, an approved instrument has to learn the meanings of 67 mg/100mls, 94 mg/100mls, 117 mg/100mls, and 184 mg/100mls. The ar

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What are the CGPM and BIPM? Is Canada a member?

Feb 20, 2018
4 min

What are the CGPM and BIPM? Is Canada a member?

Purposes: To connect evidentiary breath testing in Canada, the Criminal Code, and the Weights and Measures Act section 4(1) to the Metre Convention and the organizations created by the Metre Convention specifically the CGPM and the BIPM. To establish the primacy of the CGPM/BIPM and its SI units and vocabulary in any consideration of measurement science in Canada and internationally. To establish that Canada is a member state of the Metre Convention. To lay the groundwork for

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What is Accuracy? Techniques to Enhance Accuracy

Feb 18, 2018
2 min

What is Accuracy? Techniques to Enhance Accuracy

Purpose: To develop the concept that, in metrology, accuracy is not a number. It is something that we work towards. It does not make sense to say that a particular measurement result "is accurate". We can take certain steps to encourage accuracy such as using the mean or average of many results. The proper approach is provide a measurement result that is as accurate as possible together with a statement of the uncertainty of the measurement. Note that Hodgson, in the article

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Measurements Under the Criminal Code of Canada Use SI Units

Feb 16, 2018
4 min

Measurements Under the Criminal Code of Canada Use SI Units

Purpose: To connect the Criminal Code and its wording about concentration of alcohol in units of blood with the International system of SI units. To establish the importance of SI units and their definitions according to the CGPM when construing and applying the Criminal Code of Canada, with respect to offences defined in terms of a concentration of alcohol in units of blood. Q. I just want to show you section 253(1)(b) of the Criminal Code and I just want to ask you a quest

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What is measurement?

Feb 15, 2018
6 min

What is measurement?

Purpose: Cross-examination of a CFS scientist on the VIM. To connect "measurement" in Canadian evidentiary breath testing to "measurement" in the international literature, specifically the International Vocabulary of Metrology (the VIM Exhibit 18), referred to in most international scientific literature on measurement To define any measurement in Canada, including a measurement for a forensic purpose as a comparison. To obtain admissions from the CFS scientist as to the appli

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Traceability of Measurement Result on an Approved Instrument

Feb 14, 2018
4 min

Traceability of Measurement Result on an Approved Instrument

Purpose: To obtain an admission from the CFS scientist that the traceability of a measurement result on an approved instrument or a truck weigh scale is through the calibration of the instrument at the factory or a proper recent re-calibration by the manufacturer or factory authorized service centre. At the time of calibration a calibration curve is created to establish a relationship between the electrical signal coming off the detector in the AI or the weigh scale and the d

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Factors Influencing Reliability

Feb 13, 2018
3 min

Factors Influencing Reliability

What is "reliability" in the context of a "quantitative analysis"? What does "reliability" mean in measurement science? We have a definition of INSTRUMENTAL "reliability" from Hodgson (Hodgson, Brian T., "The Validity of Evidential Breath testing", Can. Soc. Forensic Sci. J. Vol. 41 No 2 (2008) pp. 83-96) in the paper cited by the SCC in R. v. St‑Onge Lamoureux, 2012 SCC 57 (CanLII), [2012] 3 SCR 187, <https://canlii.ca/t/ftl1g>, but: Are there additional components to instru

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Stop, Document, and Report

Feb 12, 2018
5 min

Stop, Document, and Report

Purpose: To educate the Court about good laboratory practice. To obtain an admission from the CFS scientist, that good laboratory practice requires contemporaneous documentation. To obtain an admission from the CFS scientist that good laboratory practice requires that a technician stop, document, and report whenever an anomaly occurs. To apply good laboratory practice to breath testing for a forensic purpose. Cross-examination of a CFS scientst: Q. All right. Paragraph 4.9.1

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Causation of Error v. Calculation of Drift in Precision - Evidence Based Assessment of Reliability

Feb 10, 2018
7 min

Causation of Error v. Calculation of Drift in Precision - Evidence Based Assessment of Reliability

What is the purpose in Stinchcombe/McNeil disclosure or O'Connor production of maintenance records and historical data? Crown CFS scientists are right in saying that there is no causal relationship between the historical data and the results of a subsequent subject test. Crown CFS scientists are incorrect in saying that maintenance records and historical data are irrelevant in assessing the scientific reliability of a measurement result. Control tests, cal. checks, and simula

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Heater Response Time on Guth 2100

Feb 9, 2018
7 min

Heater Response Time on Guth 2100

Purpose: To further challenge the Crown's suggestion that the anomalous low cal. checks that occurred in this breath truck were not caused by a door opening from time to time in winter. To support the O'Connor application for production of contemporaneous documentation by the QT who obtained the group of low cal. checks. Documentation would shed light on possible causes of the low cal checks, any troubleshooting attempted, and the likelihood that their cause was a problem wit

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Cross-examination about Henry's Law

Feb 8, 2018
2 min

Cross-examination about Henry's Law

Purpose: To use the cross-examination of the CFS scientist to educate the Court about Henry's Law Q. All right. In a nutshell, what’s Henry’s Law? I think – I think the Court needs to know that. A. All right. Henry’s Law is a principle in chemistry that looks at the relationship between the concentration of – I’ll use the simulator, essentially. So, the simulator contains an alcohol solution. There’s alcohol in the liquid that’s put into it. When it’s heated to 34 degr

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Wet-bath Simulators Manufacturer Specs

Feb 6, 2018
4 min

Wet-bath Simulators Manufacturer Specs

Purpose: To obtain an admission from a CFS scientist that expectation of ATC Best Practices Recommendation is for annual inspection of wet-bath simulator to ensure it meets manufacturer's specifications To obtain an admission from a CFS scientist that manufacturer's specification for a Guth 2100 simulator is 34.00 +/- .05 degrees C, not just 34.0 +/- .2 degrees C. MR. BISS: Q. Now, can you just – sorry – can you just tell us a little bit more – we’ve been talking a lot abou

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Uncertainty of Measurement is Not Novel Science

Feb 5, 2018
3 min

Uncertainty of Measurement is Not Novel Science

Purpose: To obtain an admission from a CFS scientist that uncertainty of measurement is not novel science. A. ...So, it’s a static measurement uncertainty where you use the results of the previous year. You take the average and you take the variability associated with that, and that is used to apply the analysis of the blood sample in this particular case, until the next year. So, we’ve just switched over to the 2016 M-U data, for 2017. Q. You just used the words ‘measur

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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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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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