Tentative Identification Flashcards
What are some early methods of identifying a person?
- criminals were marked by brands, tattoos, or disfigurement
- detailed written physical description was ID
- officers often had to memorize faces of known criminals
What was the Bertillon System?
- first developed by Louis Bertillon
- included physical attributes and measurements (averages were determined for populations)
- Louis brother Alphonse adapted this for police use (it included 14 characteristics with 5 ranks - shout to be unlikely 2 people would rank the same)
- worked for some time, but collapsed
What is the first question investigators must answer in an investiation?
who is the victim?
- if there is no answer, unlikely suspects or witnesses will be found
what is tentative ID?
gives a possible ID for a person, but needs confirmation
What 2 components make up tentative ID?
- Evidence from crime scene (drivers license, labels on medication)
- description of victim biology
What is a Forensic Anthropologist and what do they do?
- medically qualified consultant for the police that specializes in identification and examination of human skeletal remains
- help create biological profile of victim
- need to understand taphonomy
Which bones are used to estimate sex?
- pelvis
2. skull
What 3 features of the Pelvis can be used to differentiate between the sexes?
- pelvic inlet/opening
- pubis
- sacrum
How can the pelvic inlet be differentiated between male and female?
Male - narrow and noncircular
female - wide and circular
Which feature of the pelvis is best for sex estimation and how does it differ between sexes?
Pubis - most reliable for sex estimation but doesn’t preserve well
Male - acute (<90 degrees)
Females - approx. 90 degrees
How is the sacrum expressed between the two sexes?
Male - turned inward and approx. equal in length and width
Female - turned outward, short, and wide
What features on the skull can be used to differentiate between the sexes?
- cranium size
- forehead
- mastoid process
how are the features on the skull expressed for males and females?
cranium
- male: large ; female: medium to larger
forehead
- male: low in height, sloped ; female: high in height, vaulted, rounded
mastoid process
- male: pronounced ; female: diminished/absent
why is juvenile sex estimation difficult to determine?
- sex is not expressed on skeleton until puberty
- however, DNA from teeth can be used
What factors can help with age estimation?
- dentition
- ossification
- suture lines
How is dentition used to approximate age?
- by observing the presence of developing teeth and eruption patterns
- only valuable for juveniles **
What is ossification and how can it be used to estimate age?
- replacement of cartilage with bone
- different bones mature at different rates (can estimate age into mid-20s)
**What are two problems with using bone ossification to age juveniles?
- ## since sex doesn’t appear on a juveniles skeleton until puberty, ossification won’t be useful for age
Why is age harder to estimate in adults?
- changes in the body start to happen as we get older:
- bone density, pubic bone changes, tooth wear, arthritis
- only wide estimate can be provided
what are suture lines and how can they help determine age?
- fibrous bands of tissue that connect the bones of the skull
- juveniles - more open
- young adult - gradually close
- elderly - majority are fully closed
- provide large range for adults but more precise for children*
What 3 features on the skull can be used to determine ancestry?
- eye sockets
- nose
- incisors
What are the three main ancestries used for ancestry estimation?
- African descent
- Asian descent
- European/white descent
Differentiate between the three ancestries using identifying features
African: - square eye sockets - wide nasal cavity - smooth incisors Asian: - circular eye sockets - small, rounded nasal cavity - shoveled interior of incisors White: - oval eye sockets - long, narrow nasal cavity - smooth incisors
What is a limitation to ancestry estimation?
- many people are mixed race and may not fit into one specific category
What are normative standards? What do we use them for?
- reference set of data on a morphological trait based on samples of normal individuals of a known morphological trait
“average measurements from populations” - used to determine sex, ancestry, age, stature
What are some problems with normative standards?
- requires standards from population being studied
- standards for one race cannot be applied to all members of that race
- standards for NA cannot be applied to other countries
- new standards constantly developed
What is stature and how is it measured?
- stature refers to the height of a person
- estimated by measuring long bones in body (femur or humerus)
What are some limitations to stature?
- stature is not static (people shrink over time)
- stature record is often self-reported = inaccurate
What do Forensic Artists do?
- sketch fresh faces
- if person is decomposed, they sketch the person’s face as if they were alive
- works with pathologist if severely disfigured
What are some methods used for facial reconstruction?
- clay markers are used to approx. skin thickness (based on normative standards)
- computerized methods (often are too lifelike and hinder recognition)
