Nature's Tiny Detectives

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A little bug can make a huge difference when it comes to helping investigators determine time of death in homicide cases.

"We make an effort to collect every kind of insect we can find, we'll sort out which ones will contribute the most to understanding the case from an insect's standpoint," said Jimmy Olson, of the Texas A&M Department of Entomology.

Olson said the best insect evidence in terms of death, comes from a family of flies referred to as blow flies.

"They are usually the first to arrive and lay eggs on a corpse or carcass immediately, within minutes to a few hours after death," said Olson.

By gathering the actual bugs, examiners are able to look closely at the stage of development, appearance, and the temperatures the bugs were exposed to, to approximate the age of the specimen.

"The hotter it is, the faster the growth. The colder it is the slower they grow," said Olson. "We have models that can adjust for the various temperatures, and we can fairly accurately determine how long that it would take for a, let's say a fly, to get into the stage we collected at the death scene."

Olsen said, examiners can then use the evidence to determine when the egg was laid on the carcass, and exposed to fly activity; which in turn gives investigators insight into the length of time between death and discovery of the body.

"Some have gotten as close to a couple of hours, within at least a twelve hour period, with the right kind of collection and processing of the information," said Olson.

However, Olsen points out that a body which has been concealed, can create a delay in the time, to when the bugs are able to get to the body.

But all things considered, sometimes nature's tiniest pests can be man's best detectives.