Established Fields of Expert Evidence
- 1 General Medical Practitioner
- 2 Medical Specialists
- 3 Drug Trafficking
- 4 Gangs
- 5 Firearm Forensics
- 6 Injuries
- 7 DNA Analysis
- 8 Psychology and Psychiatry
- 9 Dog Tracking
- 10 Computer-related Forensics
- 11 Forensic Pathology
- 12 Serologist
- 13 Blood Stains
- 14 Forensic Toxicologist
- 15 Footprint Analysis
- 16 Fingerprints
- 17 Arson-related Forensics
- 18 Other Sciences
- 19 Credibility of Witnesses
- 20 Other Social Science
- 21 Legal Topics
- 22 Non-scientific Areas
- 23 Failed Qualifications
General Medical Practitioner
- an "expert witness in family medicine permitted to give opinion evidence on the diagnosis, prognosis and treatment of injury of all parts of the body, including neck, back and shoulder"
- "qualified as a duly qualified general medical practitioner, licensed to practice medicine in Nova Scotia, and qualified to give opinion evidence on the diagnosis, prognosis and treatment of human beings"
- "emergency medicine diagnosis and treatment"
- "orthopaedic surgeon qualified as an expert to give opinion evidence in the diagnosis, prognosis and treatment of knee injuries"
Experts have been qualified in several issues related to gangs:
- workings of a motorcycle gangs 
- meaning of tear-drop tattoo in street gang 
- nature and characteristics of the Hells Angels organization; the main purposes and activities of the Hells Angels organization and whether they constitute the facilitation or commission of serious criminal offences that afford a material benefit to its members.
- "evidence on the subject of the forensic analysis of firearms and ammunitions, including firearm identification, the identification of fired ammunition components as well as ballistics and toolmark identification"
- toolmark and firearms identification
- "give expert opinion evidence on the subject of the forensic analysis of firearms and ammunitions, including firearm identification, the identification of fired ammunition components as well as ballistics and toolmark identification"
- expert in "the theory, operation and identification of firearms", "the examination and identification of fired and unfired ammunition components", "the examination and identification of toolmarks", "the theory and operation of the comparison microscope", "the theory and practice of ballistic assessment".
- "qualified as a duly qualified general medical practitioner, licensed to practice medicine in [the province], and qualified to give opinion evidence on the diagnosis, prognosis and treatment of human beings"
- "identification of bodily fluids and the forensic aspects of DNA typing."
- DNA experts will not be able to testify as to the likelihood of accidental transfer of DNA.
Problems in DNA evidence can include the possibility of DNA transfer between people as well as confirmation bias where the testers know the identity of the suspect.
- R v Lafferty, 1993 CanLII 3409 (NWT SC), per Vertes J - also includes detailed summary of analysis process
- e.g. R v Doan, 2013 BCCA 123 (CanLII), per curiam
- Erin Murphy, "The ARt in the Science of DNA" (2008) 58 Emory L.J. 489
Psychology and Psychiatry
Before a judge should consider expert evidence of a specific tracking by a particular dog, the court there must be enough evidence establishing:
- the reliability of the dog breed; and
- the reliability of the specific dog.
The court should be satisfied with the evidence of the following regarding the dog:
- dog's training
- success rates
- susceptibility to distractions, such as irrelevant scents, cats or other dogs.
The handler is expected to give sufficient detail on "the process, sequence and outcome of the tracking, preferably supported by contemporaneously or near contemporaneously compiled notes." 
The trial judge should always give a warning to a jury that "such evidence should be evaluated in terms of the facts of the particular case, and that it falls into the category of evidence in respect of which special care needs to be exercised because the source of the evidence, the dog, is not able to be made subject to the usual check and balance of the court system - cross-examination."
Cases where dogs have been qualified:
- qualified as an expert "dogmaster dealing with the use of dogs in criminal investigations, tracking, and for identifying the location of human scent"
Defined area of qualification:
- area of computer forensics involving the identification, extraction, preservation, and interpretation of storage and recovery of data from electronic media
- child exploitation investigations in relation to peer to peer file sharing networks
- peer to peer file sharing programs including GigaTribe, Limewire, Shareaza, etc.
- the use of EnCase computer forensic software 
- “the operation and function of Facebook as a social media portal, and the interpretation of Facebook account records”
R v Wainwright, 2012 BCPC 123 (CanLII), per Wainwright J at para 69
R v Pelich, 2012 ONSC 3611 (CanLII), per Dunnet J at para 29
R v Pelich, 2012 ONSC 3224 (CanLII), per Dunnet J
R v SDP, 2012 SKQB 330 (CanLII), per Dovell J
R v Benson, 2010 SKQB 459 (CanLII), per Gerein J
- SDP, supra
- R. v. Moazami, 2013 BCSC 2398 (CanLII), per Bruce J
When Qualification is Not Needed
- Using Techonology From User's Perspective
It should not be necessary to have the expert testify as to the "basic functions" of computer storage devices. The suggestion seems to be that basic functionality of any appliance is not in need of proof. Similarly, it should not be necessary to qualify an expert to speak to the use of electronic devices, social media website, and other internet applications.
- Text Messaging
It should not be necessary to have someone testify as to the "sequence and lapsed timing of messages" in a messaging application.
- Cell Towers
There may be no need to for expert qualification for the interpretation of cellphone records or description on how cell phones transmit data to towers.
- Child Exploitation
It was also found to be valid for a layperson to describe child pornography websites and the search terms and file named associated with them. There is some suggestion that even the workings of file-sharing programs do not require expert qualification.
R v Wonitowy, 2010 SKQB 346 (CanLII), per Dufour J at para 46 - in context of an ITO for a search warrant on a child pornography case
- R v Soh, 2014 NBQB 20 (CanLII), per LaVigne J
- R v Ambrose, 2015 ONCJ 813 (CanLII), per Paciocco J, at para 56
R v Hamilton, 2011 ONCA 399 (CanLII), per curiam
R v Singh 2015 ONSC 6823 (CanLII), per Coroza J
R v Browne, 2017 ONSC 5060 (CanLII), per Coroza J
R v Campancioni 2016 ONSC 4615 (CanLII), per Gareau J
- Campancioni, ibid.
- "opinion evidence in that field including expressing an opinion as to the causes of the injuries suffered by the deceased and the causes and times of their deaths"
- "opinion evidence with respect to the cause of injuries to the human body and the cause of death".
- "forensic pathology, including the cause and effect of serious injury and sudden death."
- "forensic biologist who was qualified as an expert in relation to the identification of bodily fluids and DNA analysis".
They may need to specify whether the topic of serology concerns the identification of blood, saliva, sweat, semen, or vagina fluids.
R v N.C., 2007 CanLII 5691 (ON SC), per Sproat J
R v Rayner, 2007 PESCTD 22 (CanLII), per Cheverie J at para 106 ("forensic biologist with expertise in the area of identification of bodily fluids and the analysis and interpretation of DNA profiles")
R v Lafferty, 1993 CanLII 3409 (NWT SC), per Vertes J ("expert evidence on the identification of bodily fluids and the forensic aspects of DNA typing")
- "field of forensic bloodstain pattern analysis and to interpret the physical events that give rise to the shape, location, size and distribution of bloodstains" of a "crime scene in order to interpret the physical events that gave rise to its origins."
- "opinion evidence in relation to the absorption, distribution and elimination of drugs and alcohol and poisons in the human body, the pharmaceutical and toxicological effects of drugs, alcohol and poison in the human body, and the effects of drugs on the human body with respect to the operation of a motor vehicle"
- "opinion evidence in the absorption, distribution and elimination of alcohol in the human body, in forensic toxicology and the effect of alcohol consumption on the human body."
- "opinion evidence about the absorption, distribution, and elimination of drugs and alcohol in the human body as well as the pharmacological and toxicological effect of alcohol, drugs and poisons on the central nervous system"
- "opinion in the area of forensic toxicology, specifically the ingestion, absorption and elimination of alcohol in the human body, the calculation of blood/alcohol concentrations in the body, the theory and operation of approved instruments and the effects of alcohol upon the human body with respect to the operation of motor vehicles"
- "qualified to give expert evidence with respect to the pharmacological and toxicological effects of drugs, alcohol and poisons on the human body and with respect to the absorption, distribution and elimination of drugs, alcohol and poisons in the human body"
- "the interpretation of toxicological reports and findings"
- "the measurement of alcohols and drugs in bodily fluids and solutions, and the suitability of the samples for analysis"
- "the effect of drugs and alcohol on performance and behaviour, including on the ability of individuals to operate a motor vehicle;
- "the administration and interpretation of drug influence evaluation procedures"
Forensic Aloholic Specialist
- "Forensic Alcohol Specialist and he was qualified as an expert to provide opinion evidence in regards to the absorption, distribution and intake of alcohol in the body"
- "forensic alcohol specialist employed with the RCMP forensic laboratory in Halifax was qualified as an expert in the effects of alcohol on the human body and in absorption and elimination rates of alcohol from the human body"
- R v Greenwood, 2010 ONSC 912 (CanLII), per Durno J at para 18
R v Lyth, 2013 ABPC 281 (CanLII), per Skene J at para 34
- R v J.R., 2006 CanLII 22658 (ON SC), per T Ducharme J, at para 51
- R v Dhanjal, 2011 ONSC 742 (CanLII), per Miller J at para 14
- R v Daneluzzi, 2009 ONCJ 398 (CanLII), per Harris J at para 19
- R v Steven Vance Rasmussen, 2013 NBPC 2 (CanLII), per Duffie J at para 21
- R v Stevens, 2007 NSSC 148 (CanLII), per Murphy JJ at para 18
Footprint analysis has been controversial and not always accepted.
- "comparison, identification and analysis of fingerprints, which indicates the examination of scenes of crime for latent fingerprints, the use of Automated Fingerprint Identification System (A.F.I.S.) and the search and comparison of fingerprint files in order to establish identity"
- a Forensic Identification Specialist qualified as an "expert in the identification, comparison and individualization of fingerprints".
- "determination of origin, cause and circumstances of the fire"
- "determining the cause and origin of a ... fire, in understanding burn patterns, the location of the "seat" of a fire, and its movement during the course of a burn" 
- "forensic chemistry in the field of accelerant analysis, identification and analysis"
R v Fournel, 2012 ONSC 375 (CanLII), per Hennessy J
see also R v Alpine, 2008 BCPC 508 (*no CanLII links)
R v O'Brien, 2002 YKTC 45 (CanLII), per Lilles CJ
R v Jonkman, 2012 SKQB 511 (CanLII) "expert in fire investigation, cause and origin"
- R v Payette, 2010 MBQB 73 (CanLII), per Duval J
- Elliott v Royal Insurance Company of Canada, 1995 CanLII 4495 (NS SC), per A Boudreau J
- "facial mapping"
- "ear print" identification
- Crime scene analysis including staging 
- identification based on gait of walk.
- handwriting evidence permitted despite experts inconclusive evidence
- Forensic entomology
- “the function, effect, examination, diagnosis and repair of electrical work, problems and hazards” in relation to an Occupational Health and Safety prosecution
- evidence on the "cultural mores within particular communities".
- R v Clarke ,  2 Cr. App. R. 425 (C.A.)
- R v Dallagher ,  1 Cr. App. R. 195
- R v Clark, 2004 CanLII 12038 (ON CA), per Moldaver JA
- R v Aitken, 2012 BCCA 134 (CanLII), per Hall JA at para 63
- R v Garniss, 2011 ONSC 6559 (CanLII), per Ray J
- R v Farnham, 2016 SKCA 111 (CanLII), per Ryan-Froslie JA
R v Shafia, 2016 ONCA 812 (CanLII), per Watt JA, at para 240
Credibility of Witnesses
A judge should not simply accept an expert's opinion on credibility.
Other Social Science
- the meaning of the "code of silence" and its effect on witness's willingness to tell the truth.
- determining a community standard, typically in reference to an obscenity charge
- interpreting Patois
General expert evidence on false confessions has been excluded as it was not necessary, while opinion specific to the case has been permitted.
- R v Boswell, 2011 ONCA 283 (CanLII), per Cronk JA
R v Sidey, (1980), 52 CCC (2d) 257 (Ont. C.A.), 1980 CanLII 2864 (ON CA), per Brooke JA
R v Prairie Schooner News Ltd. and Powers, (1970), 1 CCC (2d) 251, 1970 CanLII 1059 (MB CA), per Freedman JA
R v Great West News Ltd., Mantell and Mitchell,  4 CCC 307, 1970 CanLII 1064 (MB CA), per Freedman JA
R v Red Hot Video Ltd., 1985 CanLII 633 (BC SC), per Nemetz J
- e.g. Referenced in R v Masters, 2014 ONCA 556 (CanLII), per Tulloch JA
- R v Bonisteel, 2008 BCCA 344 (CanLII), per Levine JA at paras 66, 69 - suggests that a proper jury instruction will suffice
- expert in laws of certain US states on a specific topic
- "brokering residential mortgages, including NIQ mortgages"
Similar issues have been disqualified: