Plastic print
Limitations of using bone ossification to age juveniles
Normative standards
Latent fingerprint
Biological profile: Female
Biological profile: age (and stature) of juveniles
Positive ID
Limitations of tentative ID
Limitations of normative standards
Biological profile: male
Mitochondrial DNA
Tentative ID
Biological profile: (age and) stature
Bertillonage
Visible print
DNA Databank
Biological profile: African
Sources of DNA: Dead person
Biological profile: ancestry
Nuclear DNA
Sources of DNA: Live person
Identification
Automated Fingerprint Identification System (AFIS)
Biological profile: European
To properly compare fingerprints...
Biological profile: Asian
Identification methods
Three patterns of fingerprints
Biological profile: age (and stature)
Biological profile: age (and stature) of adults
Two types of DNA
Steps in identification
Biological profile: sex
DNA Comparison
Three fundamental principles/characteristics of fingerprints
Loop, whorl, and arch
Differences due to sex, population, and nutritional levels. Duration of ossification varies in published databases - some publish start of ossification, others how long it takes to complete; some break ossification into several stages; reference sample may not match remains
Early method of anthropomorphic identification created by Alphonse Bertillon (1879). A system of identification using 14 physical characteristics scored with five rankings. The system was premised on the false idea that all characteristics are inherited independently, causing the major flaw that for the probability of two people having all the same ranks for characteristics is too rare, but because many characteristics are inherited together the probability of two people sharing some features is quite high. It was replaced by fingerprinting, which is now used alongside DNA and dental records.
May be more than one person who fits description; items with body may not belong to body, so ID must be confirmed.
Eye orbits - square/rectangular Nasal cavity - wide Incisors - smooth Jaw - prognathic (outward) Nasal bridge - flat
(1) A fingerprint is an individual characteristic. No two are alike. (individual) (2) A fingerprint remains unchanged throughout life. (unchanged) (3) Fingerprints have general ridge patterns that allow them to be classified into three categories: loops, whorls, and arches. (classifiable)
A fingerprint made by the deposit of oils and/or perspiration, invisible to the naked eye. Can be visualized using fingerprint powders; iodine fuming; ninhydrin; physical developer; and superglue fuming. Alternate light sources induce fluorescence of fingerprints.
Biological profile (forensic anthropology), surgical implants, facial approximation, video superimposition, materials at the scene, circumstantial, tattoos, visual ID (Positive methods: DNA, fingerprints, dental records, medical implants, frontal sinuses)
Unique, shuffling from both parents. Could get premortem sample from parents/siblings. Problem - if two same-sex siblings are missing then we can only determine that victim is the child of the parent, but not which one. Need child's DNA - if one missing had a child, it could be determined.
Cranium, forehead, brow (supraorbital ridge), mastoid process, pelvic opening, sacrum, subpubic angle, femur. Female pelvic features more exaggerated/wider. Male cranium features more robust. Cannot be determined in juveniles who have not yet gone through puberty.
Must be compared to antemortem record to be of any use. DNA gives profile, not ID. Compare DNA from A (unknown body) with sample B from premortem record of tentative ID person.
Nuclear DNA: any nucleated cell; blood (white blood cells), buccal smear (epithelial/skin tissue), hair follicle (root) mtDNA: doesn't have to come from nucleus; hair shaft
Offenders convicted of serious crimes, such as sexual assault or homicide. DNA taken in investigation is not entered in databank. Additional warrant required post-conviction - samples taken during investigation destroyed. DNA comparison can be from databank or family member or personal item.
Stature regression equations based on long bone length
Age can only be presented as a range. In juveniles, the range is narrow and more precise - based on growth. In adults, range can be very wide - based on degeneration which is highly variable.
First question asked in death investigation. To determine the killer, identity of victim must be known. Often, when victim is not identified, the crime is not solved.
Compare unknown to known (UK) and must have premortem record
Eye orbits, nasal cavity, incisors, jaw, and nasal bridge. Challenging to assess in mixed populations. Determinations for sex, stature, and age usually require known ancestry to improve accuracy.
Family line, maternal inheritance
Eye orbits - circular Nasal cavity - small, rounded Incisors - shovel-shaped Jaw - either flat or prognathic (outward) Nasal bridge - either angled or flat
Converts images of fingerprints into digital minutiae to make 1000s of comparisons per second - makes no final decisions about identity
Assumption that humans are proportional; challenging to asses in mixed populations; may not include all of human variation; standards may not exist for every population; similar populations may not be transferable (black Americans =/= black Africans)
Fresh body - blood, tissue, hair root. If decomposed or skeletonized - bone marrow, teeth (dentine, under protective enamel) mtDNA: hair shafts
A statistical term to describe the baseline of what is normal or average within a given population
1. Is the victim human? 2. Describe the victim biologically 3. Tentative ID 4. Positive ID
A fingerprint made when the finger deposits a visible material such as ink, dirt, or blood onto a surface.
Cranium - smaller Forehead - high in height, vaulted Brow - Smaller Mastoid process - diminished Pelvic opening - wide, circular Sacrum - short, wide, flat Subpubic angle - wide (right angle) Femur - narrow, angled inward
It might be this person; provides a potential name to a victim. Based on description, biological profile, items associated with body, case history, ID documents.
Cranium - larger Forehead - low, sloped, rounded Brow - pronounced Mastoid process - pronounced Pelvic opening - narrow, not circular Sacrum - longer, thinner, pointed inward Subpubic angle - narrow (acute) Femur - thick, straight
Centres of bone ossification/epiphyseal fusion, dental eruption, length of long bones (infants only)
A fingerprint impressed in a soft surface
It is this person; provides a definitive name to a victim. Tentative ID determined first so that options are narrowed down. Determined through DNA, fingerprints, dental/medical records. Cannot be anyone else.
Bone wear and degenerative changes (such as arthritis), changes to pubic symphysis and auricular surface, smoothing and obscuring of cranial sutures
Eye orbits - oval Nasal cavity - long, narrow Incisors - smooth Jaw - flat Nasal bridge: angled
Nuclear DNA and Mitochondrial DNA
