Role of Law Enforcement
Law enforcement should expect to deal with often "sophisticated criminal" and so should not be expected to be governed by "the Marquess of Queensbury rules". 
The police are expected to sometimes resort to "tricks or other forms of deceit" when engaged in the investigation of crime.
Unless the police engage in "dirty tricks", courts should not be engaging in determining "good taste or preferred methods of investigation".
R v Rothman,  1 SCR 640, 1981 CanLII 23 (SCC), per Lamer J ("It must... be borne in mind that the investigation of crime and the detection of criminals is not a game to be governed by the Marquess of Queensbury rules. The authorities, in dealing with shrewd and often sophisticated criminals, must sometimes of necessity resort to tricks or other forms of deceit, and should not through the rule be hampered in their work.")
- Rothman, ibid.
R. v. Skinner, 1992 CanLII 4015 (MB QB), per Scollin J, at p. 14 ("Absent "dirty tricks", the courts should not set themselves up as the arbiters of good taste or of the preferred methods of investigation. It is unrealistic to demand chivalry from those who must investigate what are often heinous offences against blameless victims. ...the courts should not be so indulgent as to preserve the accused from himself and his own untrammelled tongue")
R v Roberts, 1997 CanLII 3313 (BC CA), per Hall JA at para 14
R v Bonisteel, 2008 BCCA 344 (CanLII), per Levine J, at para 89
R v Figliola, 2012 ONSC 4560 (CanLII), per Whitten J, at para 95
- Investigative Detention
- Warrantless Arrests
- Warrant Arrests
- Authorized Searches Under s. 487
- Seizure of Property
Authority by Police Type
RCMP peace officers have "primary investigative jurisdiction concerning crimes committed in relation to national security or designated protected persons or designated protected sites".
The taking of notes during the course of an investigation is not simply as an aide memoire. They have an obligation to make notes.
It is important for the judicial fact finding process that significant facts be recorded and not left to the "whim of memory".
Where police fail to take contemporaneous notes, their testimony may be considered unreliable and may not be admitted.
Intentional failure to make notes may have negative consequences if it associated with a Charter breach. However, there is no known principle that says that incomplete notes, by themselves, amounts to a breach of an accused right to full answer and defence under s. 7 adn 11(d) of the Charter.
Police should not be seen to thwart the objectives of Stinchcombe by making less accurate notes.
Wood v. Schaeffer, 2013 SCC 71 (CanLII), per Moldaver J at para 67 ("...police officers do have a duty to prepare accurate, detailed, and comprehensive notes as soon as practicable after an investigation")
R v Lozanovski, 2005 ONCJ 112 (CanLII), per Feldman J at para 14 ("It is important to the proper functioning of the judicial fact-finding role that significant facts be recorded by police and not left to the whim of memory.")
R v Tweedly, 2013 BCSC 910 (CanLII), per Greyell J, at para 160 ("it is important to recall it has been held innumerable times in our courts that police testimony, without the advantage of contemporaneous notes, is unreliable and often not admitted into evidence for that purpose.")
R. v. Zack,  O.J. No. 5747 (Ont. C.J.) at para 6 ("In my view, the absence of the questioned observations in his notebook lead to the conclusion that those observations were not, in fact, made at the time but are perhaps something that over the course of time the officer has come to believe that he saw")
- R. v. Vu,  3 SCR 657, 2013 SCC 60 (CanLII), per Cromwell J, para 70 - Officer intentionally avoided taking notes
R v Bailey, 2005 ABCA 61 (CanLII), per Hunt JA at para 43 to 44
R. v. Eagle,  O.J. No. 2867 (Ont. C.J.)(*no CanLII links)
referencing the "Martin Report" ("The statement should emphasize that disclosure requirements after Stinchcombe cannot be thwarted by making less accurate or less comprehensive notes.")
R v Satkunananthan, 2001 CanLII 24061 (ON CA), per curiam at para 78
- Abuse of Process by Law Enforcement
- State and Police Misconduct as a Sentencing Factor
- Peace Officers