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"
- Jando v Kung, 1994 CanLII 9076 (AB QB) at para 83
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"
- R v Hutchinson, 2011 NSSC 361 (CanLII) at para 19
- "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) - also includes detailed summary of analysis process
- e.g. R v Doan, 2013 BCCA 123 (CanLII)
- 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:
- R v Sherman,  BCJ No. 2472; R v Rackley, 1996 CanLII 8296 (ON SC); R v Klymchuk (2000), 155 CCC (3d) 423; R v Nguyen, 1999 BCCA 98 (CanLII)
- R v Holmes, 2002 CanLII 45114 (ON CA) at para 37
- Holmes at para 37
- Holmes at para 37
- Holmes at para 37
- qualified as an expert "dogmaster dealing with the use of dogs in criminal investigations, tracking, and for identifying the location of human scent"
- R v Rayner, 2007 PESCTD 22 (CanLII) at para 72
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 
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.
See also: R v Baxter 2009 ONCJ 16 (CanLII)
R v Wainwright, 2012 BCPC 123 (CanLII) at para 69
R v Pelich, 2012 ONSC 3611 (CanLII) at para 29
R v Pelich, 2012 ONSC 3224 (CanLII)
R v SDP, 2012 SKQB 330 (CanLII)
R v Benson, 2010 SKQB 459 (CanLII)
- R v SDP, 2012 SKQB 330 (CanLII)
R v Benson, 2010 SKQB 459 (CanLII)
R v Wonitowy, 2010 SKQB 346 (CanLII) at para 46 - in context of an ITO for a search warrant on a child pornography case
- "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".
There may be need to specify whether the topic of serology concerns identification of blood, saliva, sweat, semen, or vagina fluids.
R v N.C., 2007 CanLII 5691 (ON SC)
R v Rayner, 2007 PESCTD 22 (CanLII) 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) ("expert evidence on the identification of bodily fluids and the forensic aspects of DNA typing")
- "field of forensic blood stain pattern analysis and to interpret the physical events that give rise to the shape, location, size and distribution of blood stains" 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"
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) at para 18
R v Lyth, 2013 ABPC 281 (CanLII) at para 34
- R v J.R., 2006 CanLII 22658 (ON SC), at para 51
- R v Dhanjal, 2011 ONSC 742 (CanLII) at para 14
- R v Daneluzzi, 2009 ONCJ 398 (CanLII) at para 19
- R v Steven Vance Rasmussen, 2013 NBPC 2 (CanLII) at para 21
- R v Stevens, 2007 NSSC 148 (CanLII) 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)
see also R v Alpine, 2008 BCPC 508 (*no link)
R v O'Brien, 2002 YKTC 45 (CanLII)
R v Jonkman, 2012 SKQB 511 (CanLII) "expert in fire investigation, cause and origin"
- R v Payette, 2010 MBQB 73 (CanLII)
- Elliott v Royal Insurance Company of Canada, 1995 CanLII 4495 (NS SC)
- "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 a Occupational Health and Safety prosecution
Credibility of Witnesses
A judge should not simply accept an expert's opinion on credibility.
R v Marquard, 1993 CanLII 37 (SCC),  4 SCR 223 ("A judge or jury which simply accepts an expert's opinion on the credibility of a witness would be abandoning its duty to itself determine the credibility of the witness")
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)
R v Sidey, (1980), 52 CCC (2d) 257 (Ont. C.A.) (*no link)
R v Prairie Schooner News Ltd. and Powers, (1970), 1 CCC (2d) 251 (*no link)
R v Great West News Ltd., Mantell and Mitchell,  4 CCC 307(*no link)
R v Red Hot Video Ltd., 1985 CanLII 633 (BC SC)
- e.g. Referenced in R v Masters, 2014 ONCA 556 (CanLII)
- R v Bonisteel, 2008 BCCA 344 (CanLII) at paras 66, 69 - suggests that a proper jury instruction will suffice
- expert in laws of certain US states on a specific topic
- e.g. R v Murray, 2014 ABPC 112 (CanLII) - laws relating to wildlife in Alaska
- "brokering residential mortgages, including NIQ mortgages"
- R v Nguyen, 2014 BCSC 55 (CanLII) at para 35
Similar issues have been disqualified: