Preuve démonstrative

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• < Preuve

General Principles

Demonstrative evidence includes charts, models, and experiments. They are used as tools to assist the judge in their understanding the of case. They are not "real evidence" is the strictest meaning as they are not objects that form part of the incident.

Demonstrative evidence is also called "illustrative evidence"

The courts are entitled through their gatekeeping function to assess whether to admit demonstrative evidence or other aids to assist fact-finding.

With demonstrative evidence, there is no need for formal authentication. Instead, the only standard is that of whether the evidence is relevant and whether it is an accurate representation of what it is supposed to depict. The primary consideration of the court is whether the item can assist the court or whether it warps or distorts the fact-finding process.

Demonstrative evidence is frequently excluded where it has too great a prejudicial effect by creating "emotional responses such as pity, revulsion, or contempt."

Experiments and Re-Enactments

Experimental evidence is a procedure to confirm a hypothesis or demonstrate a known fact. It is admissible as demonstrative evidence.

Where the experimental evidence is relevant and materials it will tend to be admitted, unless the discretionary exclusion rule is applied.

Experimental evidence "is often, and at times routinely, admitted at trials."

If the evidence requires inferences using special knowledge, the adducing party will need to admit it as expert evidence.

The courts generally are very cautious about allowing demonstrative evidence in the form of in-court experiments as the environment of a court does not allow for a good duplication of the events at issue. This includes video re-enactment performed by officers.

As a general rule, the relevancy and admissibility will depend on the degree of accuracy the recreation is to the original event.

Experiments in more controlled situations are more likely to be admitted. A ballistics expert who takes a firearm used in an alleged shooting can be permitted to perform tests on the weapon to determine its accuracy.

Anytime that experiments are admitted before a jury, limiting instructions should be given.

Slideshows

A PowerPoint slideshow summarizing text messages is not to be put into evidence. Rather it is a illustrative tool of evidence already in evidence.

Demonstrative aids are not meant to be "tools for advocacy or to paint a picture of one party's position."

Summaries and Charts

Summary of evidence into a chart or table can assist the judge "in understanding the entire picture represented by voluminous documentary evidence."

Compendiums are not "anathema to the law."

Where the jury are given a copy of a chart it is important that the judge give instructions that the charts are not evidence and are merely aids.

Summaries should be verified for correctness either by inspection or through cross-examination of the maker.

Generally, summaries should be based on admitted evidence.

Animations

Comptuer animations depicting moving objects can be of great assistance. However, since it can overwhelm the testimony that it attempts to assist, it must be treated as "re-enactment" evidence.

Views

A “view” is where the trier-of-fact, be it judge or jury, is permitted to attend the location of an event at issue in trial to better understand the evidence. The view may be requested by either party or on the judge’s motion under s. 652:

View

652 (1) The judge may, where it appears to be in the interests of justice, at any time after the jury has been sworn and before it gives its verdict, direct the jury to have a view of any place, thing or person, and shall give directions respecting the manner in which, and the persons by whom, the place, thing or person shall be shown to the jury, and may for that purpose adjourn the trial.

Directions to prevent communication

(2) Where a view is ordered under subsection (1), the judge shall give any directions that he considers necessary for the purpose of preventing undue communication by any person with members of the jury, but failure to comply with any directions given under this subsection does not affect the validity of the proceedings.

Who shall attend

(3) Where a view is ordered under subsection (1), the accused and the judge shall attend.
R.S., c. C-34, s. 579.

– [http://canlii.ca/t/ckjd#art652

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For a detailed review of law, see R c Polimac, 2006 CanLII 40110 (ON SC), OTC 1234, par Wein J

Some courts have taken the position that a view is not a form of evidence, but is merely an aid to understanding the evidence.

Appellate Review

The decision to allow a view is a discretionary one and should not be interfered with unless it was "unreasonable."

"Interests of Justice"

The meaning of the phrase "interests of justice" changes depending on its context within the Code.

The order is made where it “is in the interest of justice”. This requires that the viewing of the location add something to the evidence. While the viewing itself does not amount to evidence, it is intended to be an aid that helps facilitate an understanding of the evidence.

Consequently, the view can be taken even after the close of evidence.

The decision to allow a view is an exercise of discretion.