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FM4.1-5,FM14.{4,8} | Identification — PBL Case

CLINICAL SETTING

A skeletal remains case is referred to the forensic medicine department. A construction worker discovered bones while digging in a forested area on the outskirts of the city. Police have recovered a nearly complete skeleton, some decomposed clothing (female-pattern garments), fragments of hair, and a partially damaged wristwatch with a woman's name scratched on the back: 'Meera'. A missing persons report filed 18 months ago describes a 32-year-old woman, Meera Sharma, who disappeared while travelling. Her dental records from a local clinic are available. Her elderly mother provides a buccal swab for DNA comparison. You are the forensic pathologist tasked with establishing: (a) Is this a human skeleton? (b) If human, what can be determined about biological profile (sex, age, stature, race)? (c) Can this individual be positively identified as Meera Sharma? (d) Is there any evidence of cause of death?

Trigger 1: Biological Profile — Establishing Identity Parameters

Skeletal examination findings: - Pelvis: sub-pubic angle 100°, wide greater sciatic notch, oval pelvic inlet, ventral arc present - Femur: length 43 cm, head diameter 42 mm - Skull: smooth supra-orbital ridges, rounded orbital margins, small mastoid process - All major long bone epiphyses: fully fused - Medial clavicle epiphysis: fully fused, smooth surface - Teeth present: all 32 teeth (third molars fully erupted); multiple dental restorations present - Gustafson's assessment on right lower canine: total score = 7

DISCUSSION POINTS

Using the pelvic, femoral, and skull findings, determine sex. How confident are you in this determination, and what is the accuracy of pelvis-only sex determination?
Estimate the age using: (a) epiphyseal fusion status, and (b) Gustafson's formula (Age = 11.43 + 4.56 × 7). What does concordance between these two methods mean for your report?
Calculate stature using the femur (Stature = 2.15 × 43 + 72.57). Does this match the missing person report? How does stature uncertainty affect identification strength?

Click to reveal Trigger 2: Dental Comparison and Records Matching (discuss previous trigger first!)

Trigger 2: Dental Comparison and Records Matching

The dental records from Meera Sharma's dentist show: - Dental chart from 2021: upper right first molar restored with amalgam (tooth 16); upper left second premolar with composite filling (tooth 25); no other restorations documented Skeletal examination of skull: - Tooth 16: large amalgam restoration present - Tooth 25: composite filling consistent with the described restoration - All other teeth show no restorations - Dental chart match: 2/2 documented restorations concordant

DISCUSSION POINTS

What level of identification confidence does dental record comparison provide in this case? Is 2/2 restoration concordance sufficient for positive identification, and what makes dental records reliable?
What is 'antemortem-postmortem (AM-PM) data comparison' in DVI protocol? How does it differ from simply comparing features?
If the dentist's records had been destroyed in a fire and no ante-mortem dental records existed, which alternative identification methods would you pursue and in what order?

Click to reveal Trigger 3: DNA Evidence and Final Identification Opinion (discuss previous trigger first!)

Trigger 3: DNA Evidence and Final Identification Opinion

DNA analysis results: - Post-mortem DNA source: femoral bone marrow - Reference sample: buccal swab from Meera Sharma's mother (Mrs. Kamla Sharma) - STR analysis: 15 loci compared; 14 loci show allele sharing consistent with first-degree maternal relationship; 1 locus shows a mutation (acceptable) - Statistical likelihood ratio: 4.2 million (probability this is NOT her daughter = 1 in 4.2 million) Additional finding: a healed fracture of the right radius (mid-shaft) with callus formation noted. Police records confirm Meera Sharma fractured her right wrist in a road accident two years before disappearance.

DISCUSSION POINTS

Synthesise all identification evidence (biological profile, dental records, DNA, healed fracture, personal effects). Which evidence is positive identification and which is corroborative? Formulate a combined identification opinion.
What does the likelihood ratio of 4.2 million mean in plain language for a courtroom? How do you explain false positive and false negative in DNA identification to a jury?
Identify evidence of possible cause of death or injury: are there any findings in this case that should prompt further enquiry? What is your forensic obligation if no cause of death can be determined from skeletal remains?

Learning Issues

Research these questions and bring your findings to the discussion.

[FM4.1] What is the systematic approach to biological profile determination from skeletal remains, and what is the accuracy of each method?
[FM4.2] How does Gustafson's method estimate age from a single tooth, and what are its limitations for Indian populations?
[FM4.4] What is the significance of medial clavicle fusion for age estimation beyond 25 years?
[FM4.5] How does the DVI protocol prioritise and integrate multiple identification methods, and what constitutes positive versus presumptive identification?
[FM14.8] What is the medico-legal significance of a healed antemortem fracture in skeletal identification, and how does radiological comparison of ante-mortem records contribute?