Autopsy & forensics

General

Identification


Resident / Fellow Advisory Board: Lorenzo Gitto, M.D.
Deputy Editor-in-Chief: Patricia Tsang, M.D., M.B.A.
Lindsay Ninivirta, M.D.
Rebekah Jacques, M.H.Sc., M.D.

Last author update: 13 February 2023
Last staff update: 22 January 2024

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PubMed search: Forensic identification

Lindsay Ninivirta, M.D.
Rebekah Jacques, M.H.Sc., M.D.
Page views in 2023: 772
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Cite this page: Ninivirta L, Jacques R. Identification. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/forensicsidentification.html. Accessed March 28th, 2024.
Definition / general
Essential features
  • Scientific / comparative methods of identification:
    • Fingerprint comparison
    • Comparative dental radiography
    • Surgical hardware and implants (with unique numbers)
    • Radiographic comparison
    • Deoxyribonucleic acid (DNA)
  • Nonscientific methods of identification:
    • Circumstantial evidence:
      • Jewelry
      • Clothing
      • Eyeglasses found on body
      • Location of the body (residence, car registered to an individual)
      • Dentures
      • Medical alert bracelets
      • Papers or identification cards found with the body
    • Visual identification
    • Distinctive marks:
      • Tattoos
      • Scars
      • Piercings
      • Birthmarks
      • Other cutaneous lesions
    • Physical attributes:
      • Biological sex
      • Apparent age
      • Apparent ethnicity
      • Body length
      • Body weight
      • Acquired and congenital anomalies
      • Prior surgeries or medical procedures
      • Head hair color (caution: can be dyed)
      • In skeletal remains, a biological profile needs to be completed by an anthropologist
  • Disaster victim identification process:
    • Phase 1: scene (processing human remains and property at the disaster site)
    • Phase 2: postmortem (detailed examination of human remains in mortuary)
    • Phase 3: antemortem (collection of missing person data from various sources)
    • Phase 4: reconciliation (matching postmortem and antemortem data)
Terminology
  • Mass disaster identification
  • Mass casualty identification
Overview
Importance of identification
  • Identification of unknown deceased and human remains is critical for ethical, legal and humanitarian reasons
    • Identify deceased individuals and notify families
    • Establish identification for legal and statistical reasons
    • Administrative record of an individual's death (death certificate and official records)
    • Record of identity for ceremonial and burial practices
    • To allow for legal proceedings
  • Reference: INTERPOL: Disaster Victim Identification (DVI) [Accessed 6 October 2022]
Nonscientific methods in the identification of deceased individuals
  • Circumstantial evidence:
    Clothing on the decedent can function as means to collect evidence of identification of the decedent

    Clothing on the decedent
    can function as means
    to collect evidence of
    identification of the decedent



  • Visual identification:
    • Visual confirmation of the identity of the deceased individuals by a living human, such as a relative or friend (Forensic Sci Int Synerg 2021;3:100154)
    • Limitation:
      • Alteration in physical features caused by death (e.g., postmortem changes such as corneal clouding, postmortem hypostasis, pallor and muscle flaccidity) may be profound and can lead to doubt for family and friends making visual identifications (J Forensic Sci 2018;63:662)
      • Injury, decomposition, coupled with the emotional state of the deceased's friends or relatives may lead to misidentification (J Forensic Sci 2018;63:662)
  • Distinctive marks:
  • Physical attributes:
    • Comparison of physical attributes used to establish identification, leading to tentative or presumed identification (Acad Forensic Pathol 2016;6:361)
    • Process:
      • Record of physical attributes at time of autopsy, compared to antemortem records (Am J Forensic Med Pathol 2006;27:200)
      • Photographs of the face and body, using a scale with the unique case number, documents and preserves the appearance at the time of identification (Am J Forensic Med Pathol 2006;27:200)
      • Physical attributes used for identification:
        • Biological sex
        • Apparent age
        • Apparent ethnicity
        • Body length
        • Body weight
        • Acquired and congenital anomalies
        • Prior surgeries or medical procedures
        • Head hair color (caution: can be dyed)
        • In skeletal remains, a biological profile needs to be completed by an anthropologist
    • Limitation:
      • Some surgeries and medical procedures are more common in a population (i.e., appendectomy, as compared to a pancreaticoduodenectomy); in the proper context, a pancreaticoduodenectomy would carry a higher discriminatory value
      • Comparison to known characteristics of an individual including medical records, government issued photo identification, etc. (Acad Forensic Pathol 2016;6:361)
Comparative scientific methods
  • Scientific means is the ideal method for identifying the deceased
    • There are 5 means to perform scientific identification through a comparison of the antemortem to postmortem record:
      • Fingerprints
      • Dental
      • Surgical numbers on surgical hardware
      • Radiology
      • DNA
    • Expertise in different fields is required to perform the comparison of the postmortem to antemortem record; both forensic pathologists and their pathology assistants arrange and facilitate the acquisition of the postmortem record for the experts
  • Fingerprint comparison:
    • System of identification based on the classification and comparison of finger ridge patterns and minutiae (Forensic Sci Res 2018;4:293)
    • Process:
      • The science of fingerprints, their classification, retrieval from records and methods of recording typically lie in the domain of police procedure
      • The forensic pathologist's role is to facilitate the process of obtaining the postmortem fingerprints
      • Fingerprints are unique (no 2 fingerprints have been found to be identical, including among monozygotic twins, who share the same DNA) (Forensic Sci Res 2018;4:293)
      • To establish identity based on fingerprints, an antemortem record must exist for the deceased to serve as a comparison
      • Fingerprints can be uploaded into databases such as the Automated Fingerprint Identification System (AFIS) for comparison, which does not require a tentative identification for comparison (NAME: Standard Operating Procedures for Mass Fatality Management 2010 [Accessed 6 October 2022])
      • Skin from a decomposed body may detach in a glove-like fashion, which can be slipped over the hand of an investigator so that classifiable prints can be made (S Afr Med J 2005;95:665)
      • It is unnecessary to amputate fingers to obtain fingerprints
      • In case of diffuse rigidity or charring, a local dissection of the tendons at the base of the hands will help opening the fingers to obtain fingerprints
      • Mummified tissue may need to be rehydrated to obtain fingerprints (Acad Forensic Pathol 2016;6:338)
      • If the epidermis is missing from the fingers, it may be possible to obtain classifiable prints from the finger pads (Am J Forensic Med Pathol 2006;27:200)
    • Limitations:
      • Fingerprints can be affected by multiple factors including postmortem decomposition, chemicals and immersion changes, altering the fingerprint quality and comparison ability (Forensic Sci Res 2018;4:293)
      • In homicides, fingers can be cut out by the offender(s) to avoid fingerprinting

        Fingerprint

        Skin from a decomposed body which
        detached in a glove-like fashion is placed
        over the hand of an investigator;
        fingerprint impressions can then be made



  • Comparative dental radiography:
    • System of identification based on dental characteristics and features (Forensic Sci Res 2018;4:303)
    • Process:
      • Positive identification can often be established based on dental fillings, bony structures of the jaw, roots of teeth and sinuses, as these are unique to individuals (J Forensic Radiol Imaging 2015:3:29)
      • Examination of the dentition of the deceased may give information as to the age, nutrition and hygiene, which can be clues to identity (Open Dent J 2015;9:250)
      • Determination of age is evaluated based on crown and root development and eruption (Open Dent J 2015;9:250)
      • Identification via dental records is performed in conjunction with a forensic odontologist (dentist with forensic training) or an oral pathologist (J Forensic Radiol Imaging 2015:3:29)
    • Interpretation:
      • Antemortem record must be available for comparison to postmortem records as no central database exists (Acad Forensic Pathol 2016;6:361)
      • Dentition of all unidentified human remains should be charted and radiographed and a tooth extracted for DNA sampling if no other DNA sample is available (J Forensic Radiol Imaging 2015:3:29)

      Comparative dental radiography

      Comparative dental radiography on the
      left is the antmortem radiograph and on
      the right is the postmortem radiograph;
      the dental implant is apparent in both



  • Surgical hardware and implants:
    • Devices found at the postmortem examination that can be compared with antemortem medical records (Forensic Sci Res 2018;4:303)
    • Process:
      • Implanted devices can have unique serial numbers or lot numbers (i.e., specific to a group of implanted devices manufactured at the same time) (Forensic Sci Res 2018;4:303)

      Medical implant with serial number

      Medical implant with serial number

      Surgical implant

      Surgical (breast) implants



  • Radiographs:
    • System of identification based on antemortem radiological comparison to postmortem radiographs (Acad Forensic Pathol 2016;6:361)
    • Limitation:
    • Interpretation:
      Comparative radiography

      Comparative radiography on the
      left is the antmortem radiograph
      and on the right is
      the postmortem radiograph

      Postmortem shoulder radiograph

      Postmortem shoulder radiograph with
      evidence of surgical hardware that
      can be used to make an identification
      if antemortem radiographs are available



  • Deoxyribonucleic acid (DNA):
    • System of identification based on antemortem DNA comparison to postmortem DNA (J Forensic Radiol Imaging 2015:3:29)
    • Process:
      • DNA is a proven source for identification as the genetic information contained in a cell can connect biological relatives (J Appl Genet 2012;53:41)
      • Identification of human remains by DNA is possible because of multiple alleles and DNA regions that can be amplified and used to compare genetic patterns (J Appl Genet 2012;53:41)
      • DNA methods for identification require a sample from human remains to be compared to the biological sample of the closest living relative
      • DNA matching to biological relatives is the only method for primary identification that is independent of direct comparison, unlike other forms of scientific identification (J Appl Genet 2012;53:41)
      • Common foci that are examined include: short tandem repeat (STR), mitochondrial DNA (mtDNA) and Y chromosome (J Appl Genet 2012;53:41)
      • Routine postmortem samples should be collected and stored for all cases as future DNA analysis may be required (Am J Forensic Med Pathol 2006;27:200)
      • DNA samples collected for identification purposes must be correctly labeled, sealed, handled, stored and traceable through a proper chain of custody to avoid contamination (ICRC: Forensic Identification of Human Remains [Accessed 6 October 2022])
      • Postmortem samples include (Forensic Sci Res 2018;4:51)
        • Whole blood, fluid or tissues
        • Buccal swab if not too decomposed or if taphonomy impairs collection
        • Bone window ideally from an intact weight bearing bone (i.e., femur) as the dense cortical portion of lower limb bones tend to yield more consistently reliable DNA profiles compared to less dense spongy bone
    • Limitations:
      • Success depends on the ability to obtain a sufficient quality and quantity of DNA from the remains and the availability and willingness of family members to provide a DNA sample for the purpose of identification (J Appl Genet 2012;53:41)
      • Degradation of the postmortem sample, absence of nucleated cells and DNA extraction difficulties may be due to taphonomic and putrefactive changes that inhibit PCR techniques (J Appl Genet 2012;53:41)
      • Biological sample for DNA identification from biological relatives must be obtained with informed consent (J Appl Genet 2012;53:41)
      • A routinely obtained DNA sample can be compared with surgical specimens from the decedent, if they exist (Am J Forensic Med Pathol 2006;27:200)
      • DNA is identical for monozygotic twins (Forensic Sci Res 2018;4:303)
      • Siblings of the same biological sex cannot be differentiated based on DNA alone if the comparative reference sample is from a biological relative; other primary and secondary lines of evidence would be required
      • Dental pulp tissue is often used as a source of DNA from severely decomposed and skeletal remains; however, dentition will need to be charted and radiographed prior to extraction (Int J Forensic Odontol 2017;2:43)
      • In burned bodies or decomposed bodies, bone is often collected as a source of DNA (Forensic Sci Res 2018;4:303)
      • It is imperative that all attempts have been made to acquire a genetic profile prior to release of the body; multiple samples may need to be collected to obtain a DNA profile (Forensic Sci Int 2018;289:253)
Special considerations
  • Prior to disposition of unidentified bodies (Am J Forensic Med Pathol 2006;27:200):
    • Perform a forensic autopsy
    • Obtain radiographs
    • Chart and radiograph dentition
    • Document (including photos) clothing (with details of brand tag and size) and personal effects
    • Collect DNA sample for archiving
      • Collect blood in fresh bodies
      • Collect bone (commonly femur) in severely decomposed bodies
    • Request consultations, if required
      • Anthropology
      • Radiology
  • Identification of skeletal remains:
Disaster victim identification (DVI) / humanitarian forensic action
Board review style question #1

The antemortem image shown above is acquired from an unidentified individual. What is true about dental radiographs in the context of forensic identification?

  1. A central database exists to compare postmortem records to antemortem records
  2. If dental fillings and implants are present they can be compared to antemortem records
  3. It is not advisable to routinely perform dental radiographs of unidentified individuals
  4. There is no association between age and crown and root development
Board review style answer #1
B. If dental fillings and implants are present they can be compared to antemortem records. This is an antemortem dental radiograph showing a dental implant and fillings, which can be compared to postmortem radiographs for identification. Other features that can be used for a positive identification include bony structures of the jaw, roots of teeth and sinuses that are unique to individuals. There is unfortunately no central database for antemortem dental records and therefore locating antemortem records can be a significant challenge as the decedent's dentist must be found.

Comment Here

Reference: Forensic identification
Board review style question #2
After a house fire, 2 bodies are found. The bodies are of 2 brothers who lived in the home. Which is true about using DNA to identify the brothers?

  1. Dental enamel is a reliable source of DNA in this scenario
  2. DNA from a biological relative will not be able to differentiate between the brothers
  3. DNA from buccal swabs is the best source of DNA in burned bodies
  4. mtDNA should be used to differentiate between the brothers
Board review style answer #2
B. DNA from a biological relative will not be able to differentiate between the brothers. A biological relative's DNA sample would not be able to differentiate between the brothers in this instance as both of their biological profiles would contain different combinations of the same DNA source material from their mutual parents; therefore, using a biological sample for comparison wouldn't be able to exclude either of them. Other sources of information would need to be utilized to distinguish between the 2 brothers. mtDNA also cannot be used as the brothers would have the exact same mtDNA sequence. Dental pulp has been successfully used as a source of DNA in decomposed remains; however, dental enamel is relatively acellular and is not a good source of DNA.

Comment Here

Reference: Forensic identification
Board review style question #3

What is true about the forensic identification method shown above?

  1. Finger pads don't contain ridge detail or minutiae
  2. Fingerprints cannot be used to distinguish between identical twins
  3. If the skin is detached it can still potentially be slipped over the hand of an investigator in a glove-like fashion to obtain fingerprints
  4. Postmortem decomposition has no effect on fingerprint quality
Board review style answer #3
C. If the skin is detached it can still potentially be slipped over the hand of an investigator in a glove-like fashion to obtain fingerprints. Image of a thumb with black ink applied from an unidentified individual to obtain fingerprints. Ridge detail is visible. The fingerprints will be photographed and rolled onto fingerprint tape to make an impression that can be used for comparison to antemortem records. No two individuals have been found to have identical fingerprints, including identical twins.

Comment Here

Reference: Forensic identification
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