Mitochondrial Analysis From Hair Examinations to DNA Sequencing

1. Mitochondrial Analysis From Hair Examinations to DNA Sequencing State of Connecticut Forensic Laboratory

2. Trace Evidence • Trace evidence: items or debris found in the process of investigating a crime • Generally small in size, may be transferred when physical contact occurs between two individuals or an individual and an object. • Hairs: a commonly encountered example of trace evidence.

3. Hair • A biological outgrowth from the skin of mammals. • Three areas of a hair: Root, Shaft, Tip • Three cross-sectional regions of a hair: Cuticle, Cortex, Medulla

4. Suspect Victim Scene Object Hair Evidence • Found in many crimes, submitted to the laboratory. • Can include homicides, hit and runs, sexual assaults, kidnappings, burglaries, etc. • Can associate a suspect to a victim, weapon and/or a crime scene.

5. Why Is Hair Good Evidence? • Abundant; the average person has >100,000 hair follicles on their head alone • Easily transferable; the average person loses 100 hairs per day • Considerable variability; comparing body area alone, human hair can be from the head, pubic, anal, eye, nose, ear, underarm, leg, arm, chest, trunk, or beard area, not including the fine hair covering the entire body except on a person’s palms and soles. • Durable; hairs have been recovered from mummies dating back 2,000 years

6. Steps of Analysis • Hairs are collected from evidence submitted • Hairs are identified and preserved onto glass microscope slides • Hairs are examined both macroscopically and microscopically • If a known standard exists, hairs are compared • A report containing all the results of the comparison is written • Examiner testifies in a court of law to the results written in the report.

7. Hairs are identified from the collected debris and mounted onto glass microscope slides Type of evidence submitted is anything on which a hair could possibly be found: includes clothing, letters, guns, knives, bomb devices, bedding, car parts, furniture, carpets, flooring, tape, etc. Hairs are collected by either scraping, picking, taping or vacuuming. Processing

8. Examination • Macroscopic characteristics of hair: length, coloration, shaft shape, and texture. • Microscopic characteristics of hair include: • The hair shaft (optical cross section, diameter variation, tip appearance, buckling, artifacts, other) • The cuticle (thickness, appearance, color, damage) • The cortex [color, pigment granule size, pigment granule shape, pigment granule distribution, pigment granule density, cortical inclusions, cortical fusi (size, distribution, and density), ovoid bodies (size, distribution, and density), cortical texture] • The medulla (color, thickness, texture, continuity pattern, abnormalities) • The hair root (condition, color, tissue, cortical fusi)

9. Results A qualified hair examiner can provide the following information from a hair examination and comparison: 1. Whether there is hair(s) recovered from the item(s) submitted. 2. What the racial origin of the hair is (Caucasian-type, Negroid-type, Mongoloid-type) 3. The area of the body that the hair came from (head, pubic, body) 4. The nature of the hair’s removal from the body 5. Whether the hair has been artificially treated 6. Whether there has been damage done to the hair 7. Whether there are similarities and/or differences between the questioned hair and known sample. *How much information an examiner can provide depends upon the suitability of the hair.

10. Hair Examination Conclusions A hair examiner can conclude the following: • 1. The questioned hair exhibits similar characteristics (no significant differences are present) to the known sample. Thus, the source of the known sample cannot be excluded as being the source of the questioned hair. • 2. The questioned hair exhibits dissimilar characteristics to the known sample. Thus, the source of the known sample can be excluded as being the source of the questioned hair. • 3. The questioned hair exhibits both similarities and differences to the known sample. Thus, no conclusion can be reached as to whether the questioned hair can or cannot be excluded as coming from the same source as the known sample. • 4. The known hairs are insufficient or unsuitable for comparison purposes. • 5. The questioned hair(s) are insufficient or unsuitable for comparison purposes.

11. Further Testing: A Complement To Forensic Hair Examinations • Hair examinations can not identify a specific individual • Results can be supplemented by performing other independent analyses • Further testing will not change conclusions stated by the hair examiner • Can provide alternative and additional information about the hair Further testing is deemed suitable and/or probative based upon: • If the hair root has tissue attached, Nuclear DNA analysis • If there is no tissue and/or root, Mitochondrial DNA analysis Nuclear DNA Mitochondrial DNA

12. Mitochondrial DNA Analysis: • Mitochondria are considered the “powerhouse” of the cell • Where the energy to run cellular functions (ATP) is made • Has its own DNA (mtDNA)

13. NUCLEAR DNA Linear 2 Copies per cell Very large (3 billion base pairs) Inherited from both parents Unique to the individual (except identical twins) MITOCHONDRIAL DNA Circular Thousands of copies per cell Small (Just over 16,000 base pairs) Inherited only from the mother Not unique Nuclear DNA vs. Mitochondrial DNA

14. When Would We Use Mitochondrial DNA? • Hairs missing the Root • Old Bones, Teeth • Missing persons cases • Mass Disasters Since mitochondrial DNA has a high copy number, it is more resistant to degradation

15. Why Isn’t Mitochondrial DNA Unique? Mother All Yellow = Same mtDNA type as Mother Female Male

16. How Is Mitochondrial Testing Done • Extraction of DNA from sample • Amplification of extracted DNA, to make many exact copies of the DNA we extracted • Quantitation of amplified DNA, to determine how much DNA is there • Determine the sequence of two specific regions of the mitochondrial genome

19. Now What? • Compare sequences of questioned items to known sequences • Are they different? Case #1 Case #2 QuestionedGCATATTGCGCCTA GCATATTGCGCCTA KnownGCACATTACGTCTA GCATATTGCGCCTA *EXCLUSION *CANNOT EXCLUDE *This is a simplification, the regions scrutinized are larger, and analysis is far more complicated. This is meant to assist in a very basic understanding.

20. And Last… • Compare the attained sequence with the Mitochondrial CODIS Database • How many times does the sequence we’ve attained appear in the database • From that number, we can estimate the frequency of that sequence in the general population

21. Interesting Forensic Casework Involving Mitochondrial DNA • Tsar Nicholas II Romanov • Did we find Anastasia? • NO • Anna Alexander claimed to be the missing child of Nicholas Romanov • Her mitochondrial DNA did not match those of unearthed bones, or of maternal relative Philip of Edinburg

22. Interesting Forensic Casework Involving Mitochondrial DNA • Tennessee Vs. Ware • First case in US where mitochondrial testing was introduced. • September, 1996 • Murder case in which the only evidence found was red hairs in throat of victim and on the victim’s bed • Paul Ware could not be excluded as the source of the hairs.

23. Interesting Forensic Casework Involving Mitochondrial DNA • Connecticut Vs. Pappas • Robbery, first CT case in which mitochondrial DNA analysis was allowed in the courts • Mitochondrial DNA analysis on two head hairs from sweatshirt found on train tracks adjacent to where some of the robbed money was located • The defendant could not be excluded as the source of the questioned hair sample • Case appealed up to CT Supreme Court, who ruled that this type of testing is acceptable

24. Interesting Forensic Casework Involving Mitochondrial DNA • Connecticut Vs. Torres • Murder/Sexual Assault, verdict March, 2002 • Amount of DNA recovered not sufficient for nuclear DNA testing • Mitochondrial profile from semen matched that of the suspect *For more detail on this case, click here to see description from the laboratory’s trace section, who had a major contribution to the outcome.