Presenting Scientific Evidence in the Courtroom

• Author: Vincenzo Rondinelli
• Pages: 37-43

37

A. INTRODUCTION

The Honourable Fred Kaufman concluded his report involving the wrong-

ful conviction of Guy Paul Morin by stating, “An innocent person was con-

victed of a heinous crime he did not commit. Science helped convict him.

Science exonerated him.”1 Therein lies the conundrum of science in the

criminal justice system. “Good” science may assist in catching criminals

and exonerating the wrongfully convicted, while “bad” science may im-

prison the innocent, but distinguishing between “good” and “bad” science

is not a simple or clear task. Part of the problem may be attributed to Can-

ada’s adversarial justice system, where trial practice can be a tug-of-war

between logic and rhetoric. Logic seeks to f‌ind the truth, whereas rhetoric

seduces the listener to accept the claims of a partisan actor.

Scientif‌ic evidence presents unique challenges for lawyers, judges,

and juries. Yet, due to the complexity of criminal prosecutions, the pres-

entation of scientif‌ic evidence is sometimes necessary. Should an expert

witness make it past the gatekeeping judge,2 it will be up to counsel calling

the witness to help convey the evidence to the jury in an understandable

and memorable manner. Opposing counsel will have a dif‌ferent task. They

will attempt to expose the def‌iciencies in the expert opinion to keep the

1 The Honourable Fred Kaufman, C.M., Q.C., Report of the Kaufman Commission on

Proceedings Involving Guy Paul Morin (Toronto: Queen’s Printer, 1998) ch. VI at 1.

2 See Chapter 3.

CHAPTER 4

Presenting Scientif‌ic Evidence in

the Courtroom

Vincenzo Rondinelli