Blue Line

Investigations 101: Lessons from Shakespeare’s Macbeth

March 27, 2023  By Gilles Renaud

This review of Macbeth seeks to assist police officers enhance their investigative skills by discussing valuable lessons that Shakespeare communicated. Lessons on the dangers of demeanour evidence and of circumstantial evidence abound, to name but two, abound in this timeless play.

Leading questions to be avoided

A leading question typically calls for a yes or no type of response and is repeatedly asked in cross-examination when the questioner wishes a precise response to be given by the witness. It ought not to be asked by a prosecutor in examination-in-chief as it leads to the objection by defence counsel. Similarly, investigators ought not to suggest to witnesses what to say as such information is viewed as less than reliable, since the witness is merely parroting information. Further, your professionalism may be called into question, potentially undermining other aspects of the interview and of the case. Act 1, sc. i, of Macbeth provides a simple example: “When shall we three meet again? In thunder, lightning, or in rain?” In effect, the person questioned is only given three choices.

An example of non-leading questions is seen in Macbeth, Act 1, sc. iii:

First witch: Where hast thou been, sister?


Second witch: Killing swine.

Third witch: Sister, where thou?

Of note, Shakespeare illustrated the possibility that the person questioned by means of a leading question will nonetheless respond correctly, without selecting from the narrow options provided. An interviewer who asks a leading question may repair the error, in part, by having the witness expand on their response. If a traffic officer asked: “Was the car ‘all over the road’ as it came near you?” and is told “Yes”, go on to ask for details. At times, a full description of whatever information is sought might illustrate the knowledge possessed by the witness.

For the sake of completeness, a question that is fair and free of suggestion follows, at Act 1, sc. i: “First Witch: Where the place?” It cannot be said that to suggest that there was a place is leading, as in the case of “what time?”, “who was present?” and “how much time was involved?”, as no element of human activity is pursued without the so-called “5 W’s” questions being engaged. In the final analysis, do not ask: “Was it Professor Plum in the kitchen with the candlestick?”

Circumstantial evidence – concerns for the investigator

Macbeth, Act 1, sc. ii, includes this passage, in which a bloody Sergeant shares how the battle was fought: “… For brave Macbeth … Disdaining Fortune, with his brandish’d steel, Which smoked with bloody execution, Like Valor’s minion carved out his passage till he faced the slave, Which ne’er shook hands, nor bade farewell to him Till he unseam’d him from the nave to the chaps, And fix’d his head upon our battlements.” As a result of receiving this report, King Duncan stated: “So well thy words become thee as thy wounds; They smack of honor both. Go get him surgeons.”

What is of note is that the wounds of a coward, injured while fleeing the battle, would probably be just as impressive as those of the bravest soldier, as one cannot judge fully and fairly whether the wounds represent valour or cowardice. This is an example of the dangers of circumstantial evidence, and it must be understood that judges are vitally concerned that evidence is not assigned far too much importance without justification.

Recall that Lady Macbeth seizes the bloody knife with which her husband killed King Duncan, and smears the two guards during their sleep, in order that all apparent suspicion fall upon them.  Refer to Act 2, sc. ii, “… Why did you bring these daggers from the place? They must lie there. Go carry them, and smear The sleepy grooms with blood.”

With that introduction in mind, it will suffice if I refer to one case, R. v. Villaroman, 2016 SCC 33, [2016] 1 S.C.R. 1000, at para. 30:

It follows that in a case in which proof of one or more elements of the offence depends exclusively or largely on circumstantial evidence, it will generally be helpful to the jury to be cautioned about too readily drawing inferences of guilt… Telling the jury that an inference of guilt drawn from circumstantial evidence should be the only reasonable inference that such evidence permits will often be a succinct and accurate way of helping the jury to guard against the risk of “filling in the blanks” by too quickly overlooking reasonable alternative inferences. It may be helpful to illustrate the concern about jumping to conclusions with an example. If we look out the window and see that the road is wet, we may jump to the conclusion that it has been raining. But we may then notice that the sidewalks are dry or that there is a loud noise coming from the distance that could be street-cleaning equipment, and re-evaluate our premature conclusion. The observation that the road is wet, on its own, does not exclude other reasonable explanations than that it has been raining. The inferences that may be drawn from this observation must be considered in light of all of the evidence and the absence of evidence, assessed logically, and in light of human experience and common sense.

From the perspective of the investigators, the Supreme Court of Canada teaches you that it is necessary to delve deeply into any factual controversy and never to jump to the first, available and obvious conclusion. One helpful test that investigators might apply is to consider whether what appears to be the correct circumstantial fact may too easily be reversed or flipped.

Thus, if one cannot know which of the two choices is correct, then the investigator is no further ahead as this kind of circumstantial evidence cannot justify a finding beyond a reasonable doubt.  Consider the classic case of the person who is kneeling next to the stabbing victim and who is holding the bloody knife – a too quick conclusion that this is the person stabbing might be defeated when one flips the facts to see that the suspect has no blood on their clothing, and CCTV shows that person having left the subway 60 seconds earlier, but the deceased was struck down 60 minutes earlier.

That said, not every proposition of fact that may be flipped means that it is worthless in building a case. Consider the more dated—but none the less interesting—example of the Berlin Wall.  When the East German government was criticized for erecting a structure of such dimensions that no one could leave the Communist country, senior leaders stated that the Wall was needed to prevent capitalists from West Germany from flooding into the heaven that was the communist side. The exercise of reversing the proposition requires a serious examination of the merits of the two sides of the coin.

At the end of the day, careful investigators who have considered fully all aspects of a disputed factual controversy may ultimately conclude that the circumstantial evidence is consistent with guilt. One must not confuse the test for arrest, at an earlier stage of the investigation, with that for a finding of guilt after trial; but one must not rely too easily on easily disputed circumstantial evidence.

“Voluntary confessions are generally considered reliable as it is human nature not to wish to take blame for our wrongs and when we do, it is seen as truthful.”

This general statement, understood as expressing the reality of a person’s full and frank confession, is often the explanation given for the fact that confessions are exceptions to hearsay.  People do not generally wish to admit wrongs as it brings blame, shame and penalties. In this vein, note the following passage, from Act 1, sc. iv:

Duncan: Is execution done on Cawdor? …

Malcolm: … That very frankly he confess’d his treasons,

Implored your Highness’ pardon, and set forth

A deep repentance. Nothing in his life

Became him like the leaving it…

In effect, the law and the psychology that tends to inform the common law, such as it is, strongly supports the view that only one who is truly guilty and whose actions and words are informed by such guilt will accept responsibility and that this state of mind provides a degree of confidence that the admission is voluntary, reliable, credible, trustworthy and may thus be acted upon with no fear of error or miscarriage of justice.

Demeanour evidence – “One cannot read the thoughts of others on their face”

King Duncan stated in Macbeth, Act 1, sc. iv, “There’s no art To find the mind’s construction in the face: He was a gentleman on whom I built An absolute trust.” This comment referenced someone who betrayed him. The words that I have quoted are typically cited by lawyers, for the defence and the prosecution, in attacking the so-called value of demeanour evidence. For present purposes, investigators must be mindful of the basis rules governing the weight to be assigned to such non-verbal evidence, as explained by Justice Roger of the Superior Court of Ontario in the case of R. v. Ackerman, 2022 ONSC 5381:

Demeanour evidence alone can be a notoriously unreliable predictor of the accuracy of the evidence given by a witness as “the law does not clothe the trial judge with divine insight into the hearts and minds of the witnesses” and demeanour should not be sufficient where there are significant inconsistencies and conflicting evidence. [para 94]

More valuable means of assessing witnesses are to consider the consistency of what they have said on a material matter (internal and external contradictions) and improbabilities (exaggerations or illogical propositions). However, inconsistencies vary in their nature and importance; some inconsistencies are minor or concern peripheral subjects, others are more important or involve a material issue or something material. [para 95]

Demeanour evidence is however not completely irrelevant; for example, the way that a witness testifies, such as unanswered questions, hesitations, challenging counsel or run-on and unresponsive answers, may in certain circumstances be prudently considered by judges in their assessment of witnesses in conjunction with their assessment of all the evidence. [para 96]

In pursuing this theme, I wish to underscore that one of the next lines in Act 1, sc. iv illustrates how the eyes are generally understood to be the mirrors of the soul, especially in the case of an evil one: “Stars, hide your fires; Let not light see my black and deep desires. The eye wink at the hand; yet let that be Which the eye fears, when it is done, to see.”

Noteworthy as well are the passages that follow that contain examples of the dangers associated with demeanour evidence.  Firstly, I refer to Act 1, scene v, “… Your face, my thane, is as a book where men May read strange matters. To beguile the time, Look like the time; bear welcome in your eye, Your hand, your tongue; look like the innocent flower, But be the serpent under it…”  In fact, this admonition from his wife is necessary as Macbeth’s features made plain his anxiety.

A second example is found in Act 1, scene vii, “Macbeth … Away, and mock the time with fairest show: False face must hide what the false heart doth know.”

Note taking

In Act 1, sc. iii, Macbeth informs others that their pains towards him was so kind and important that they are “… registered where every day I turn The leaf to read them…” The leaf being the middle-ages equivalent of a notebook. This passage reminds investigators that all information must be recorded fully.

Final thoughts

I end by noting this comment by Macbeth in Act 1, sc. iii: “[Aside.] Come what come may, Time and the hour runs through the roughest day.” The citation serves to make plain that many hours must be devoted to complex cases and there are always long days to be devoted to the vocation of policing.

Gilles Renaud will soon retire after serving 28 years as a member of the Ontario Court of Justice. Previously, he was an Assistant Crown Attorney in Ottawa and a prosecutor with the War Crimes and Crimes Against Humanity Section of the Federal Department of Justice. He began his legal career as a defence counsel and has written nine books on the law, including three in French.

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