The Body in Question: Exploring the Cutting Edge of Forensic Science
Notes by J. Zimmerman
- Beyond reasonable doubt.
- Who was John - or Jane - Doe.
- Suspicious circumstances.
- Time of death.
- Cause of death.
- The guilty party.
- The mind of the criminal.
- In the courtroom.
"Every contact leaves a trace."
L'enquete criminelle et les methodes scientifiques
Everyone intrigued by developments in the power of DNA testing and other
forensic science, or with such events as the OJ Simpson trial,
need this enthralling, readable, and thoroughly illustrated book.
"The public is no longer satisfied with motion picture and television programs that
soft-pedal the scientific process,
instead demanding more realism and better science in popular depictions of investigative procedures."
Packed with murder investigations and new techniques in USA, and Britain.
Beyond reasonable doubt
Early development of methods of determining causes of death and likely perpetrators.
Initial codification of fingerprint (friction-ridge) patterns after Sir Frances Galton's
observation of specific types of fingerprint patterns:
Initial blood typing:
- Plain arch
- Tented arch
- Simple loop
- Central pocket loop
- Double loop
- Lateral pocket loop
- Plain whorl
|A: antigen A present, antigen B absent.
|B: antigen B present, antigen A absent.
|O: neither antigen present.
|AB: both antigens present.
Initial ballistics analysis:
- Began 1835 with Henry Goddard's comparison of bullets.
- Determined the burglary was staged by the butler!
Who was John - or Jane - Doe?
- The coroner and the autopsy.
- Initial examination of six sites for body hair.
- Dental characteristics.
- Skulls and bones. Including the reconstruction of a person's features from their skulls.
What is discovered at the scene determines if further investigation is required:
- Tools for collecting evidence.
- How fingerprints are investigated, including prints in discarded gloves.
- Foot and tire prints.
- Blood and biological fluids, including blood patterns.
- Trace evidence.
- Fire and explosion. E.g., the reconstruction of how the Lockerbie disaster happened.
Time of death
Are they dead? No detectable heartbeat, respiration, or brain activity?
- Body temperature.
- Rigor mortis.
- Stomach contents.
- Adipocere - a corpse buried in water or wet surroundings can form this
greyish soap-like wax by chemical action on body fat.
- Cadaver fauna. The Body Farm (U. of Tennessee's Anthropological Research Facility)
measures the decay of human bodies.
- Decay products allow calculation of 'degree hours' since start of decomposition.
Cause of death
- Initial examination.
- Stages of the autopsy.
- Asphyxiation. E.g., Jonestown.
- Contusion and other injuries.
- Wounds with sharp instruments.
- Gunshot wounds. E.g., the Kennedy Assassination (Nov 22, 1963); 'the Warren Commission
published twenty-six volumes of evidence presented before it,
but did not consult a single forensic pathologist.'
- Internal examination.
- The nature of death: natural, accident, suicide, or killed by someone else.
- Toxicology screening: chemical spot tests; chromatography; mass spectrometry;
- Analysis of materials.
- Diatoms tested for in a drowned body, to determine if alive on entry into water.
The guilty party
- Eyewitnesses first register
- hair, mouth, eyes,
- then the shape of each,
- then eye color,
- and only with those in place does one register the general form of the face.
- Photo-fit and video-fit.
- Every contact leaves a trace. E.g., Wayne Williams (Atlanta, 1981).
- DNA: A brief history.
- Fragmented DNA:
- Restriction enzymes cut DNA strands into sections
but only at the site of a specific sequence of base pairs.
- Restriction fragment length polymorphism (RFLP) analysis.
- Southern blot: method (for RFLP analysis) developed by Scottish scientist Edward Southern (1975)
to detect the position of separate DNA fragments.
- Variable number tandem repeats (VNTR): detects the occurrence of a number of identical
- Disadvantages: requires a large-enough sample; DNA may be degraded by light, temperature, chemicals, etc.
- Polymerase chain reaction (PCR) DNA:
- Discovered 1983 by Kary Mullis at Cetus Corp. Awarded 1993 Nobel Prize for this technique.
- Claims to recover DNA from a single cell.
- An enzyme copies and recopies a single DNA strand: 'molecular photocopying'.
- Vulnerable to contamination.
- National DNA Information System (NDIS).
- The Innocence Project (by April 2002) has used DNA to show 104 people had spent on average
10 years in prison for crimes they had not committed.
- Bullet identification.
The mind of the criminal
The investigative methods above assume we have leads on, or actually have in hand, a suspect.
But what if we don't?
- Sherlock Holmes' predictions arose in Arthur Conan Doyle's mind because of his
teacher, Surgeon Dr. Joseph Bell.
- Psychological profiling.
- Crime Classification Manual (CCM).
- Geographic profiling.
- Analysis of handwriting and text.
In the courtroom
Case study of the O.J. Simpson trial includes:
Pictures of Nicole Simpson (found dead June 12, 1994) and description of the violence of her attack.
Obviously a crime of passion.
- "O.J. Simpson's behavior during the hours following the murders,
and later, was deeply suspicious", including the appearance of attempt to flee.
- Mark Furman's prejudice and lying under oath discredited the defense.
- Questions about contamination of samples further weakened the prosecutions case.
Case study of Wayne Williams (Atlanta serial child murderer):
- FBI profiling successfully predicted not only Williams' attributes but also his behavior in court.
The work of the crime investigators is:
- Presented at trial as evidence by the prosecution.
- Queried (often confrontationally) for validity
by the defense, who may attempt to discredit the expert witnesses by establishing:
- Break in the chain of custody (evidence could be contaminated).
- Lack of credential of the witness.
- Doubts about the validity of techniques used.
- A counter expert to contradict the prosecution data.
- Failure to meet
1993 Supreme Court Guidelines for admissibility of evidence from a theory or technique:
- The theory or technique can and has been tested.
- It's had peer review and publication.
- Its error rate is sufficiently small.
- Standards control its operation.
- Acceptance in a relevant scientific community is widespread.