R. v. Mohan (1994)
On appeal to the Supreme Court of Canada from the Ontario Court of Appeal, a decision on the
admissibility of expert evidence and the nature of expert evidence and how it pertains to
disposition. A Canadian decision similar to the American Daubert Hearings, the Mohan decision
has set the parameters and application for the admission of expert in Canada.
Admission of expert evidence depends on the application of the following criteria:
a) Relevance
b) Necessity in assisting the trier of fact (judge or jury)
c) The absence of exclusionary rule
d) Must be by a properly qualified expert
In R. v. Mohan, four counts of sexual assault on female patients ages 13-16 were laid against a
practicing paediatrician. His counsel indicated that he intended to call a psychiatrist who would
testify that the perpetrator of the alleged offences would be part of a limited and unusual group of
individuals and that the accused did not fall within that narrow class because he did not possess
the characteristics of the group (profile) however the evidence was ruled inadmissible.
The original conviction was stayed by the Court of Appeals and opened a new hearing. At issue
was the determination of the circumstances in which expert evidence is admissible to show that
the character traits of an accused person do not fit the psychological profile of the putative
perpetrator of the offences charged. The resolution of the issue involved the examination of the
rules relating to (i) expert evidence, and (ii) character evidence.
In summary, expert evidence which advances a novel scientific theory or technique is subjected
to special scrutiny to determine whether it meets a basic threshold of reliability and whether it is
essential in the sense that the trier of fact will be unable to come to a satisfactory conclusion
without the assistance of the expert.
The Supreme Court allowed the appeal but decided that the evidence should be excluded as
nothing in the court record supported a finding that the profile of a paedophile or psychopath (as
alleged by the psychologist) has been standardized to the extent that it could be said that it
matched the supposed profile of the offender depicted in the charges. The expert’s group profiles
were not seen as sufficiently reliable to be considered helpful.
http://www.canlii.org/en/ca/scc/doc/1994/1994canlii80/1994canlii80.pdf 08-01-2009
Courtesy of Cst. Jonathan BALTZER and Sgt. Tim Walker, RCMP
RAM
Combination of Rhodamine 6G, Ardrox and MBD dyes, which fluoresce when exposed to
selected wavelengths of light; used to visualize cyanoacrylate fumed friction ridge detail.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Developed in 1990 by four FBI Latent Print Examiners: Harless Cummins, Felix Peigare, Mitchell
Hollars and Tim Trozzi.
RAY
A fluorescent dye stain (a combination of Rhodamine 6G, Ardrox, and Basic Yellow 40) used to
visualize cyanoacrylate ester fumed friction ridge detail. Optimum viewing is done with an
alternate light source (450-550nm) and orange or red goggles.
R6G
See Rhodamine 6G.
RTX
See Ruthenium Tetroxide.
RUVIS
Reflective Ultra-Violet imaging system that allows visualization of friction ridge detail in the
ultraviolet spectrum.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Radial
The smaller of the two bones of the forearm, on the same side as the thumb.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Radial Longitudinal Crease
The crease that encloses the thenar area and interdigital pad 1. Below the proximal transverse
crease. Known as the ‘line of life’.
Random Sampling
See Sampling.
Rarity
Fewness or scarcity of an item, thing, or shape.
Quantitative-Qualitative Friction Ridge Analysis, David R. Ashbaugh 1999 CRC Press
Reagent
A substance or mixture used to produce a reaction.
Red Flags
Danger signs, common in latent fingerprints that may indicate a distortion in the ridge path.
Quantitative-Qualitative Friction Ridge Analysis, David R. Ashbaugh 1999 CRC Press
Redox
Reduction-Oxidation. Chemical reaction in which one or more electrons are transferred from one
atom or molecule to another. An important component of the Physical Developer and Multimetal
Deposition processes.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Redwop ™
A fluorescent fingerprint powder developed by Ed German in 1986 and given to the Lightning
Powder Company.
In the mid-1980’s, Brent Cutro, with the Illinois State Police, noticed the paint pigment on an
Oxydol box glowed under certain light wavelengths. Ed German researched this phenomenon
and found it was a substance known as Fire Orange pigment. He then established the optimal
dilution of Fire Orange pigment in lycopodium to effectively dust for latent prints. This was the
first latent print development powder tailored for blue-green wavelength excitation. Ed German
gave his new invention to Lightning Powder Co. Michael Carrick, of Lightning Powder, named the
new invention Redwop. The components of Redwop may have changed since its inception.
Redwop (powder spelled backwards) is a very fine fluorescent powder. It is especially useful on
multicolored objects but also works well on wood and vinyl. A feather or zephyr brush is the
preferred application. Optimum viewing is done with an alternate light source using blue-green
excitation (475-510 nm) and an orange filter. When competing luminescence occurs with the
background/substrate, viewing at 570 nm and a red filter or viewing with UV lighting can improve
visualization. Yellow goggles should be used to protect eyes from UV light. Redwop is noncaustic to the skin but breathing the dust particles should be avoided.
Re-examination
A re-examination is a reassessment of a conclusion(s) which can be done by the same individual
or a different individual, and done with either the original evidence or reproductions of the
evidence. The person doing the reassessment may or may not know of the original
conclusion(s). A re-examination is different from normal verification (although it can verify the
conclusion) because the intent of re-examination may be different. The intent of re-examination
is to check if other conclusion can also be determined while the intent of verification is to check
the reliability of the conclusion(s). Differing conclusions may arise due to the differing
information.
Reh, Dr. Ludwig (1894)
Dr. L. Reh was an early researcher on the hands and feet of mammals. Reh classified many of
the various epidermic formations as scales but separated the fine lines that covered the pads. He
wrote “Die Schuppen der Saugetiere” (“The Scales of Mammals”) in 1894 where he stated that
ridges did not evolve from scales, they are of secondary origin.
Reis, George
George Reis is one of the early users of digital imaging in forensics and is a knowledgeable and
prominent forensic imaging expert in the United States.
Mr. Reis started his career as a photographer, photojournalist and photo lab technician. From
1989 to 2004 he worked for the Newport Beach Police Department in California as a forensic
photographer. In 1991 he began experimenting with digital imaging technology and the following
year NBPD started using this technology for fingerprint analysis.
In 1995, George Reis founded Imaging Forensics, which provides training and consulting
services in both digital imaging and photography. Through his company he has trained personnel
from the Secret Service, FBI, US Army Crime Lab, state, county and municipal agencies. In
addition to training, Imaging Forensics provides consulting to police agencies in order to help
them transition to digital imaging technology. They also provide litigation support on criminal and
civil cases (for both plaintiff and defense).
Mr. Reis is certified by the IAI in Forensic Photography. He is a member of the Forensic
Photography and Imaging Certification Board, and a member of the Journal of Forensic
Identification editorial review board. Additionally, Mr. Reis is an alpha and beta tester for Adobe
Photoshop.
Relative Position
Proximity of characteristics to each other.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Reliable
The ability for a technique to produce consistent results.
Renoe, Alexander J. (A. J.) (1868-1939)
Renoe was a prominent United States identification expert in the early 1900’s. He learned about
personal identification from Capt. Michael P. Evans. In 1889, while working at the Illinois State
Reformatory, Renoe was asked to organize a Bertillon identification unit for the reformatory. In
1904, he added a fingerprints system. In 1908, he was asked to implement a finger print system
for the Minnesota State Penitentiary. Just a few months after this he was offered the position of
records clerk for the US Penitentiary at Leavenworth, Kansas under the Warden, Major R. W.
McClaughry. In 1914, he was appointed Chief of the Bureau of Identification for the US
Department of Justice, which was located at Leavenworth. While working in this position, Renoe
developed the extensions to the Henry System that were used by many police departments,
including the FBI. He held this position until 1923 when this finger print section was combined
with the National Police Bureau’s records to form the Identification Section of the Federal Bureau
of Identification in Washington D.C. Renoe was appointed technical expert in the reorganization.
Among his other accomplishments, in 1921 Renoe was elected as the 2nd president of the IAI and
served two terms in this position.
Repeatable
The ability for a technique to produce consistent results by a single person.
Reproducible
The ability for a technique to produce consistent results by others.
Reproducibility is a hallmark of science for physical events, i.e., physical phenomenon must occur
independent of the person carrying out the investigation. Reproducibility is not a hallmark of
analytical sciences where the acceptability of the conclusion is based on sound reasoning, not
based on whether the results are reproduced by others.
Reticular Layer
One of the two layers of the dermis. The layer that is furthest from the epidermis.
Reversed Image
See Image Reversal.
Reversed Color or Tones of Print
See Tonal Reversal.
Reviews, types of
Administrative Review
Peer Review
Technical Review
Verification can be used as either a review process or a re-examination process
Reyes, Victor
See State of Florida vs. Victor Reyes.
Rhodamine(s)
Family of dyes that produce fluorescence when exposed to selected wavelengths of light; used to
visualize cyanoacrylate fumed friction ridge detail.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Rhodamine 6G
A fluorescent dye stain used with an alternate light source to visualize cyanoacrylate ester fumed
friction ridge detail. Optimum viewing is done with an alternate light source (495-540nm) and
orange or red goggles.
Ridge (Friction)
See Friction Ridge.
Ridge Aplasia
Congenital absence of friction ridge skin.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Ridge Characteristics
See Characteristics
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Ridge Count
The number of ridges between the core and the delta. Used in the Henry Classification System.
Ridge Detail in Nature
John Berry (Hertfordshire) commenced publication of this esoteric journal in 1979, dealing with
his observations that the seven basic ridge detail characteristics appear throughout nature,
obvious examples being zebra and wind-blown or tidal-formed ridges and furrows on sand
surfaces. In the century prior to his research, a dozen or so discoveries had been noted in
fingerprint publications. The first issue of RIDGE DETAIL IN NATURE was circulated with
‘Fingerprint Whorld’ in 1979, featuring over seventy discoveries, many being illustrated. Since
then Berry has published twenty-five annual issues, many profusely illustrated, and with large
page counts. The journal was re-titled STRABISMUS in 1998. At the end of 2004, the total of
ridge detail discoveries was 1,556. Alice Maceo, of the Las Vegas Metro Police Department, has
lectured at I.A.I. conferences, citing many of Berry’s reported discoveries, and proffering her
theory for the phenomenon. Berry also lectured on the subject at fingerprint conferences in
several countries before his retirement in 1991. John Berry expresses his appreciation for the
reports of over thirty researchers in the last quarter century, especially his friends and excolleagues at Hertfordshire, Martin Leadbetter and Mike Walker.
Ridge Dissociation
See Dissociated Ridges
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Ridge Dysplasia
See Dysplasia
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Ridge Flow
1. The direction of one or more friction ridges.
2. A component of Level 1 detail.
SWGFAST, Standard Terminology of Friction Ridge Examination 3-23-11 ver. 3.0
Ridge Hypoplasia
Underdeveloped ridges associated with an excess of creases.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Ridge Path
1. The course of a single friction ridge.
2. A component of Level 2 detail.
SWGFAST, Standard Terminology of Friction Ridge Examination 3-23-11 ver. 3.0
Ridge Unit
A theoretical length to indicate a segment of a friction ridge. This length is approximately the
same distance as the width of a friction ridge and signifies the area around one pore.
Small section of a friction ridge containing one pore.
Quantitative-Qualitative Friction Ridge Analysis, David R. Ashbaugh 1999 CRC Press
See Friction Ridge Unit.
SWGFAST, Standard Terminology of Friction Ridge Examination 3-23-11 ver. 3.0
Ridgeology
The study of the uniqueness of friction ridge skin and its use for personal identification
(individualization).
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Ridgeology is a term developed in 1982 by Sgt. David Ashbaugh to describe the scientific
evaluation process used for friction ridge identifications.
Roquerre, Donald Daring
In 1934, in an attempt to conceal his identity, Donald Daring Roquerre mutilated his fingerprints
by conducting surgery on himself. He removed sections of skin and exchanged them with other
areas. In some fingers he merely changed the direction of the skin. In 1953 he was arrested, the
alteration of his fingerprints was discovered and he was still easily identified.
Rosaniline Chloride
See Basic Fuschin.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Rose Bengal
A fluorescent dye stain used with an alternate light source to visualize cyanoacrylate ester fumed
friction ridge detail. The results using this method were minimal and its use diminished in the
1980’s.
Ross, Marion
Marion Ross was the murder victim in a 1997 SCRO murder case involving erroneous
identifications.
See. McKie Case.
Rubber Lifter
A sheet of flexible rubber with a small amount of adhesive on one side used to lift latent prints for
preservation. The advantage of using a rubber lifter is that because of it’s flexibility, latents can
be lifted off of textured and curved surfaces. Rubber lifters are also helpful in lifting latent prints
off of paper items because they won’t rip the paper. Latents lifted with rubber lifters will have
reversed images.
Rubbing Technique
Powdering technique that can develop friction ridge detail when substrates are rubbed with
gloves or cotton dipped in powder, usually after surfaces are cyanoacrylate fumed.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Rudimentary
1. Of or relating to basic facts or principles; elementary.
2. Being in the earliest stages of development; incipient.
3. Biology. Imperfectly or incompletely developed; embryonic: a rudimentary beak.
The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2000 by Houghton Mifflin Company.
Published by Houghton Mifflin Company.
http://dictionary.reference.com/search?q=rudimentary 05-13-03
Rudimentary Ridge
Due to the definitions of Rudimentary, a rudimentary ridge could refer to either the primary and
secondary ridges or refer to incipient ridges. It is more common to see them referred to as
incipient ridges.
Also known as an incipient ridge, a nascent ridge or a subsidiary ridge.
Ruga (plural: rugae)
A fold or wrinkle. In friction ridge identification the rugae refers to friction ridges.
Ruhemann’s Purple
Colored compound that is the product of the reaction between amino acids and ninhydrin.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
Rule 16
Discovery and Inspection, section (a) (1) (G) Expert Witnesses
(2024 version)
(i) Duty to Disclose. At the defendant’s request, the government must disclose to the defendant, in writing, the information required by (iii) for any testimony that the government intends to use at trial under Federal Rule 1 of Evidence 702, 703, or 705 during its case-in-chief, or during its rebuttal to counter testimony that the defendant has timely disclosed under (b)(1)(C). If the government requests discovery under the second bullet point in (b)(1)(C)(i) and the defendant complies, the government must, at the defendant’s request, disclose to the defendant, in writing, the information required by (iii) for testimony that the government intends to use at trial under Federal Rule 1 of Evidence 702, 703, or 705 on the issue of the defendant’s mental condition.
(ii) Time to Disclose. The court, by order or local rule, must set a time for the government to make its disclosures. The time must be sufficiently before trial to provide a fair opportunity for the defendant to meet the government’s evidence.
(iii) Contents of the Disclosure. The disclosure for each expert witness must contain:
* a complete statement of all opinions that the government will elicit from the witness in its case-in-chief, or during its rebuttal to counter testimony that the defendant has timely disclosed under (b)(1)(C);
* the bases and reasons for them;
* the witness’s qualifications, including a list of all publications authored in the previous 10 years; and
* a list of all other cases in which, during the previous 4 years, the witness has testified as an expert at trial or by deposition.
Rule 701. Opinion Testimony by Lay Witnesses
(As amended to December 1, 2011)
If a witness is not testifying as an expert, testimony in the form of an opinion is limited to one that
is:
(a) rationally based on the witness’s perception;
(b) helpful to clearly understanding the witness’s testimony or to determining a fact in issue; and
(c) not based on scientific, technical, or other specialized knowledge within the scope of Rule
702.
Rule 702. Testimony by Expert Witnesses
(As amended December 1, 2023)
A witness who is qualified as an expert by knowledge, skill, experience, training, or education
may testify in the form of an opinion or otherwise if the proponent demonstrates to the court that it
is more likely than not that:
(a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to
understand the evidence or to determine a fact in issue;
(b) the testimony is based on sufficient facts or data;
(c) the testimony is the product of reliable principles and methods; and
(d) the expert has reliably applied expert’s opinion reflects a reliable application of the principles
and methods to the facts of the case.
Rule 703. Bases of an Expert’s Opinion Testimony
(As amended to December 1, 2011)
An expert may base an opinion on facts or data in the case that the expert has been made aware
of or personally observed. If experts in the particular field would reasonably rely on those kinds of
facts or data in forming an opinion on the subject, they need not be admissible for the opinion to
be admitted. But if the facts or data would otherwise be inadmissible, the proponent of the opinion
may disclose them to the jury only if their probative value in helping the jury evaluate the opinion
substantially outweighs their prejudicial effect.
Rule 705. Disclosing the Facts or Data Underlying an Expert’s Opinion
(As amended to December 1, 2011)
Unless the court orders otherwise, an expert may state an opinion — and give the reasons for it
— without first testifying to the underlying facts or data. But the expert may be required to
disclose those facts or data on cross-examination.
Rule 1001. Definitions That Apply to This Article
(As amended to December 1, 2011)
In this article:
(a) A “writing” consists of letters, words, numbers, or their equivalent set down in any form.
(b) A “recording” consists of letters, words, numbers, or their equivalent recorded in any manner.
(c) A “photograph” means a photographic image or its equivalent stored in any form.
(d) An “original” of a writing or recording means the writing or recording itself or any counterpart
intended to have the same effect by the person who executed or issued it. For electronically
stored information, “original” means any printout — or other output readable by sight — if it
accurately reflects the information. An “original” of a photograph includes the negative or a print
from it.
(e) A “duplicate” means a counterpart produced by a mechanical, photographic, chemical,
electronic, or other equivalent process or technique that accurately reproduces the original.
Rule 1002. Requirement of the Original
(As amended to December 1, 2011)
An original writing, recording, or photograph is required in order to prove its content unless these
rules or a federal statute provides otherwise.
Rule 1003. Admissibility of Duplicates
(As amended to December 1, 2011)
A duplicate is admissible to the same extent as the original unless a genuine question is raised
about the original’s authenticity or the circumstances make it unfair to admit the duplicate.
Rule 1004. Admissibility of Other Evidence of Content
(As amended to December 1, 2011)
An original is not required and other evidence of the content of a writing, recording, or photograph
is admissible if:
(a) all the originals are lost or destroyed, and not by the proponent acting in bad faith;
(b) an original cannot be obtained by any available judicial process;
(c) the party against whom the original would be offered had control of the original; was at that
time put on notice, by pleadings or otherwise, that the original would be a subject of proof at the
trial or hearing; and fails to produce it at the trial or hearing; or
(d) the writing, recording, or photograph is not closely related to a controlling issue.
Russell-Turner, William
Inventor of the Comparator.
Ruthenium Tetroxide (RTX)
Reagent used in the visualization of friction ridge detail, especially on fabrics.
SWGFAST, Glossary – Consolidated 09-09-03 ver. 1.0
A chemical used in a fuming method to develop friction ridge detail on porous items. RTX reacts
with sebaceous material leaving dark gray images. This process can be used on thermal paper
human skin, fabric, leather, glass, plastic, tape, wood, metal, stone, walls, and wet surfaces.