entomology

Daubert Standard

replaced the Frye Standard (1923) which focused on the general acceptance of scientific evidence within the particular field.

used to determine the admissibility of scientific evidence in court

To challenge expert testimony, opposing counsel may bring a pretrial motion attacking the admissibility of expert testimony. This will be done with a hearing prior to the trial.

5 factors of Daubert Standard

testability, peer review, error rate, standard and controls, general acceptance

testability

whether the theory or method can be objectively tested

peer review

whether the theory or method has been reviewed by experts in the field

error rate

The potential error rate of the technique

standards and controls

Whether there are clear standards for using the method

general acceptance

whether the theory or method is accepted by the relevant scientific community

insect evidence

in the form of adults, eggs, other developmental stages (larvae)

3 body segments of insects

head, thorax, abdomen
may have wings

insects provide evidence that may reveal

PMI (postmortem interval) –time between death and the discovery of the body

Time of the year when the crime was committed,

Location of a decomposing body

Wound location on the body

Victim identity

Abuse or restraint

survival

The most important factors for most organisms to survive are:

Suitable temperature

Correct amount of moisture

Suitable food source

Sufficient oxygen

Favorable environment

blowflies

Among the first to arrive.

putrescine and cadaverine, are released that alert the blowflies to a possible location to lay their eggs.

The female flies deposit their eggs in clusters on the body, usually in natural openings such as the mouth, nose, ear, vagina, or anus.

eggs laid where injuries are to skin

If the conditions are favorable within an hour of arriving on the dead body the female will lay approximately 50 eggs in the cluster.

Eggs will develop into larvae usually in less than 24 hours

life cycle of blowfly

Will undergo complete metamorphosis (a change in the body form) from egg, to larva, to pupa, and finally to adult.
the larvae move away from the decomposing flesh, sometimes crawling over 10 feet away from the body in search of a dry dark place to pupate.

houseflies

common in houses

May be indicators of abuse due to their attraction to urine and feces

flesh flies

deposit living larvae onto the flesh

coffin flies

About the size of fruit flies

May be the only fly to reach the body

beetles

carrion-associated beetles (decaying flesh) typically arrive after flies to eat the fly larva.

other insects to arrive at body

Ants, Bees, Wasps, Spiders

These creatures feed on the decomposing body or the eggs and larvae of flies and beetles

insects and pmi estimates

PMI because blowflies arrive within minutes of death

examples of pmi estimates

if only blowfly eggs are present and no blowfly larvae are present, then the estimated PMI is usually less than 24 hours because the eggs have not developed into larvae

No insects are found; it may indicate that the body was totally covered or refrigerated.

entomology evidence

used in combination with other evidence to estimate PMI (rigor mortis, liver mortis, algor mortis)
not as reliable if death is within two days

crop analysis

The organ in the larva that stores food before it becomes a pupa.

The larvae feed on the victim and store the ingested food in their crop.

No digestion occurs within the crop so the victim's DNA is not harmed.

The ingested tissues and DNA of the victim in the crop can be amplified and analyzed.

Determining victim’s exposure to drugs, alcohol, or toxins based on insect evidence

analysis of insect evidence

Determining the victim’s physical conditions based on insect evidence

Egg or maggot masses found on different parts of the body may indicate:

Wounds or injury sites (rope laceration, knife wounds, bullet holes)

House flies may indicate child or elder abuse if found on bedding, crime scene or the victim (Attracted to feces and urine)