General and Specimen Collection

The autopsy is conducted by a forensic pathologist or a pathologist who is knowledgeable about trauma and sudden death. All findings should be described in an autopsy report which is completed after the examination. A pathologist may dictate the findings at the time of the exam or document them on a worksheet and dictate them later. Injuries in suspicious case and homicides should be photographed. Some jurisdictions are also using video cameras. All information from a case must be retained in the decedent's case file for later review by all interested parties.

The most important information determined at the autopsy is the cause of death. The manner of death may not be obvious and scene investigation may be essential in determining the manner of death. Besides documenting signs of injuries and natural diseases, a pathologist must collect evidence which may be helpful in determining the manner of death.

Evidence which can be collected include:

1. Blood — Blood must be collected for drug screens, blood typing and DNA comparisons. Blood for drug analyses can be collected in any container, but one containing fluoride oxalate prevents clotting and contamination from bacteria. The blood should be refrigerated and may even be frozen, except for DNA

testing and blood group typing. Blood should be collected in every case because it is always better to have it and not use it than discover later that it was needed but never obtained.

2. Urine — Urine is good for screening many drugs, especially drugs of abuse. If a urine screen is negative, blood usually does not have to be analyzed, unless specific drugs not apparent on routine screening are suspected.

3. Anal, vaginal, and oral swabs — Cottons swabs are used to collect seminal fluid and sperm in suspected cases of rape. All swabs should be air-dried prior to packaging. Often, a swab may be made on a glass slide.

4. Foreign material — Hairs, threads, fragments of wood, metal, and any other foreign material should be collected in suspicious cases.

5. Clothing — Every article of clothing in homicides and suspicious cases should be dried and bagged. A pathologist should not cut clothing off a body in a suspected homicide. For example, if a pathologist cuts through the hole of an entry wound in a gunshot case, the hole will be distorted and future evaluation regarding point of entry or exit might be impossible.

6. Hair— Head hair samples are routinely taken in homicides. Pubic hair samples are submitted if a sexual assault is suspected. Hair samples should be taken from more than one site. Combings of the pubic hair in suspected sexual assault cases should be submitted separately.

7. Vitreous humors — This fluid is good for screening certain drugs, especially alcohol. It is also used to measure glucose and electrolytes, especially sodium, chloride, urea, and creatinine.

A pathologist may submit other fluids and organs from a body for drug testing as deemed necessary. Some labs prefer different tissues and fluids such as bile and brain. A pathologist usually knows the lab's preference.

Specimen ccollection is usually performed by law enforcement investigators. Ideally, crime scene technicians or their representatives attend the autopsy and help the pathologist collect further evidence. All evidence and specimens should be placed in separate containers. Each container is labeled with the pathologist's or investigator's name, date, autopsy number, and type of specimen. A chain of custody begins at this point and continues until the disposition of the specimen is completed.

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