Friday, March 25, 2011

Conducting An Autopsy


First of all, it’s important to know that not everyone who dies has an autopsy.  Although for us mystery writers, it’s pretty much going to apply all the time.  Our books are full of murders, and suspicious deaths.

An autopsy is also known as a post-mortem examination.  It is usually carried out when a death is traumatic, unusual, or sudden and unexpected.  Common situations that warrant this investigation are as follows: violent deaths, deaths at the workplace, deaths that are suspicious, sudden or unexpected, deaths that occur while incarcerated or in police custody, deaths that are unattended by a physician that occur within 24 hrs of being admitted to a hospital or when admitted while unconscious and it’s never regained prior to death, deaths that occur during medical or surgical procedures, deaths that occur during an abortion whether medical, self or illegal, a found body whether known or unidentified, before a body can be cremated or buried at sea, at the request of the court.

There are 9 basic steps to conducting an autopsy.  These can sometimes overlap, and be performed in a different order depending on the situation.

- Identification of the Deceased
- Photography of the body, clothed and unclothed
- Removal of any trace evidence
- Measuring and weighing the body
- X-raying all or parts of the body
- External examination of the body
- Dissection of the body
- Microscopic examination of any tissues removed during the examination
- Toxicological and other laboratory examinations

Identification of the Deceased
Critical step.  There can be no doubt as to who the deceased is.  Usually it’s not an issue.  Family members or friends come forward and offer this information.  If not, photos, fingerprints, and dental records may be used.

Photography of the body, clothed and unclothed
Also frontal and profile photos of the face and body are taken.  Every injury, scar, birthmark, tattoo and unusually physical feature must be recorded.

Removal of any trace evidence
The body is carfully scrutinized for hairs, fibers, fluid stains, and other bits of trace evidence.  Sometimes  the coroner will use a magnifying glass, or alternative lighting such as laser, ultraviolet or infrared.  Clothing is carefully removed and packaged.

Measuring and weighing the body
This is recorded along with age, sex, race, hair and eye color.

X-raying all or parts of the body
Can reveal bone and some types of internal soft-tissue injuires.  They can also help identify the shape of the weapon used (if applicable).  They can also find bullets, or fragments in the body.

Sidenote:  A bullet may enter the chest, strike a rib or the spinal column, deflect downward through the diaphragm and settle in the pelvic area.  An extensive search of the chest will not find the bullet while an X-ray of the abdomen or entire body might reveal it.

External examination of the body
This should commence at the crime scene if possible.  The ME or coroner should visit the scene before the body is moved.  Hands of victims should be covered with paper bags to protect trace from under fingernails.  The body is usually wrapped in clean plastic sheets and then placed in a clean body bag.  This allows any trace evidence that may fall off the body to be collected, and uncontaminated.

Dissection of the body
This is for the purpose of internal examination.  This is accomplished by making a Y-incision.  An incision extends from each shoulder down to the lower end of the breast bone, the third continues down the midline of the abdomen to the pubis.  The ribs and clavicles (collarbones) are then cut with a saw or shears and breastplate is removed, exposing  the heart, lungs and blood vessels of the chest.  The heart and lungs are removed, and are sent for testing blood type, DNA analysis, and toxicology.

Next the ME weighs each organ in the abdomen area and these are weighed and examined.  Samples are taken for microscopic examination.
Stomach contents might help determine last meal and time of death.

Lastly the ME looks for evidence of head trauma or skull fractures, and then examines the brain.

After each organ has been examined and samples taken for testing and analysis, all organs are returned to the body and the incisions are sutured closed.

Microscopic examination of any tissues removed during the examination
“The removed tissue samples are “fixed” in a formalin solution and then embedded in a block of paraffin.  These paraffin blocks make slicing the specimen into very thing sections easier.  The slices are placed o a glass slide and stained with biological stains for viewing under a microscope."

Toxicological and other laboratory examinations
All collected bodily fluids and tissues are sent for testing, and can reveal a lot.  Stomach contents may reveal drug use from within hours of the person’s death.  Urine and bile may indicate drugs used during the past several days.  Hair may show signs of chronic heavy metal (arsenic, mercury, lead).  Blood is useful for alcohol levels and many other drugs.

Upon Completion of the Autopsy
The ME or Coroner prepares a final report detailing all findings.  And despite the fact each may use his own method and style, the report will include the following: external examination, evidence of injury, central nervous system (brain and spinal cord), internal examination of chest, abdomen and pelvis, toxicological examinations, other laboratory tests, opinion.
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Information for this post (along with some direct quotes) obtained from Howdunit Forensics A Guide for Writers by DP Lyle MD