Entomology Review- Forensics

What is the complete Blow Fly Metamorphosis life cycle?

1st:adult, 2nd:eggs, 3rd: 1st, 2nd, 3rd instar, 4th pupa

After how many hours is entomological evidence the most accurate?

72 hours

What is the body farm?

A body farm is a research facility where decomposition can be studied in a variety of settings.

Laceration

A wound or irregular tear of the flesh

What conditions affect colonization of the body?

Altitude, geographic regions, sun exposure, inside or outside a house, buried or above ground, hanged, burned, wrapped in material, and in a vehicle.

What are the first groups of insects to arrive at a dead body?

Blowflies

What slows down algor mortis?

Body in bed, wrapped in blankets, thick clothing, extra body fat, body laying on concrete, and a hot and humid environment

Besides humans, who else practices their skills at the Body Farm

Cadaver Dogs

What are the different scenarios/conditions that bodies have been studied in at the Body Farm.

Clothing, no clothing, sun, shade, buried, in water, and in car trunks

What speeds up algor mortis?

Cold environment, body laying on concrete, and the victim is small

What are some different ways a medical examiner can identify the body?

DNA, fingerprints, dental records, friend/family, and skeletal clues

What are the 4 parts of a Forensic Entomologists job?

Identification of insects, Collection and preservation of insect for evidence, Determining PMI, and Testifying in court to explain insect related evidence

What does a Medical Examiner do?

Identifies the body, collects the body for examination and autopsy, determines cause and manner of death, and determines time of death

Eye appearance

If eyes are open, cloudiness develops n 2-3 hours. If the eyes are closed, cloudiness develops in 24 hours

Algor mortis

If the air temperature is around 20 C, a body will lose 0.75 degrees C each hour for the first 12 hours. After 12 hours, the body will lose 0.4 degrees C each hour until the body temperature and the room temperature is the same

Explain what is meant by Algor Mortis

If the body is cold and it is hot outside then the body as been there for awhile

Digestive Contents

If there is partially digested food in the stomach, death occurred 0-3 hours after the last meal. If the stomach is empty but the small intestine is full, death occurred 4-6 hours after the last meal. The small intestine will be empty if death occurred at least 12 hours after the last meal. The large intestine will be empty if death occurred at least 30 hours after the last meal.

Which muscles are the last to experience rigor mortis?

Large muscles (EX: Leg muscles)

Livor mortis

Lividity begins showing 1-2 hours after death. Lividity becomes fixed at 6-8 hours

Rigor mortis

Rigor mortis begins 1-2 hours after death. Body is in full rigor 8-12 hours after death. After 24-48 hours, muscle breakdown begins and muscles relax.

Abrasion

Scrape of the skin due to something abrasive

Which muscles are the first to experience rigor mortis?

Small muscles (EX:f face muscles)

Stage 4- Dry Decay

Soft tissue gone and skin of the body is mummified

Stage 1- Fresh Stage

Stiffening, discoloration, and relaxation of the body

How can you figure out how long ago someone was poisoned?

Stomach contents, ocular fluid and blood, urine and bile, and hair and nails

What weather data is collected in a crime scene?

Temperature

What factors affect insect devlopment?

Temperature, moisture, wind, time of day, season, exposure to elements, and variations among insects.

Contusion

bruise, injury

What can slow down decomposition?

coldness

Stage 3- Advanced Decay

less insect activity, impacted by temperature (insect activity slower in the cold and faster in heat)

Which factors affect insect development?

temperature, moisture, wind, time of day, season, exposure to elements, and variations among insects

What is carrion?

the decaying flesh of dead animals

How does Livor Mortis indicate whether a body has been moved after death?

Fixed blood seen on a non-dependent location indicates that a body has been moved after death.

What are the two types and orders of insects most used in investigations?

Flies (diptera) and Beetles (coleoptera)

If a body is found in a fire and the arms are extended, this possibly suggest what?

Foul play- Something was preventing the arms from curling up

What can speed up decomposition?

Heat

Medical examiners only do autopsies if there is a suspicion of what or what?

Homicide or foul play

Where do female blowflies mostly lay their eggs?

In natural body openings or wounds

How does temperature affect fly growth?

Increased temperatures can speed up fly growth

Stage 2- Bloat and Active Decay

Insect activity- blowflies, maggots, yellow jackets, cells bursting, and gas buildup

Why is the oldest maggot the most important to Forensic Entomologists?

It can help determine time of death

What will a cadaver dog do to signal its handler when it finds human remains?

It will bark and/or lay down

What four causes of death can be listed on an autopsy report?

Natural death, homicide, suicide, and accidental death

What are some things that can be identified by 'reading' saw marks?

Number of teeth per inch in the tool used, false starts, skips, type of saw used, width, how wide the teeth are, curve width, and how the saw was used

What is PMI?

Post Mortem Interval- Determines when death happened

Where is the Body Farm located?

The University of Tennessee

Why do beetles have to stored desperately from other insects?

The beetles will eat the other insects

What factors affect PMI estimates?

The body enclosed or wrapped in material, other insects or species present, and drugs or poison in the body

What is species succession?

The colonization of species

What is algor mortis?

The cooling of the body after death

What is necrophagous?

The feeding on corpse or carrion

What is livor mortis?

The gravitational setting of the blood

Which maggot is the most valuable when determining time of death?

The largest maggot

What is rigor mortis?

The stiffening of muscles after death

What is Forensic Entomology

The study of insects

What unique ability do coffin flies have?

They can dig their way underground to coffins

What is special about Coffin Flies?

They can dig their way underground to coffins or bodies not in a coffin

What is the goal of a Ground Penetrating Radar System in Forensics?

To find bodies buried under soil, concrete, and in rubble

What is the purpose of forensic facial reconstruction with an unknown skull?

To identify the individual so that the case can be solved