Capobianco Trial: Forensic Entomologist Estimates Time of Death

September 26, 2016, 7:11 AM HST · Updated September 26, 9:58 AM
Wendy Osher · 0 Comments
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A forensic entomologist testified on Friday in the ongoing murder trial of Steven Capobianco.

Dr. M. Lee Goff examined nine containers containing insect specimens that he received from the Maui Police Department as part of the homicide investigation involving the death of Charli Scott, who was 27-years-old and five months pregnant with an unborn child fathered by the defendant.

Goff testified that there were two separate egg-laying events: One that occurred between 1 p.m. and 7 p.m. on Feb. 10, 2014; and a second event starting by around 6 a.m. on Feb. 12, 2014.

When asked if those times would have been consistent with a person being killed between 9 to 11 p.m. on Feb. 9, 2014, Dr. Goff agreed it would be consistent saying blow flies are generally considered inactive at night.

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In approximately the 35 hours between those two egg-laying events, Dr. Goff testified that there would have been a period of inactivity between 7 p.m. on Feb. 10, 2014, and 6 a.m. on Feb. 12, 2014.

Prosecuting attorney Robert Rivera asked if the inactivity would be consistent with “wrapping a dead body in a blanket and taping the ends of the blanket with masking tape or other material.”  Dr. Goff responded saying, “That would be a possibility.”

Forensic Entomology:  When Insects Become a Part of a Legal Proceeding

Dr. Goff explained that entomology is the study of insects, and forensic entomology is anytime insects become part of a legal proceeding, which includes three sub-specialties: score product (ie: when insects are in a sold product such as cereal); structural (ie: when proper precautions are not taken and termites get into a building and begin to consume it); medical legal/medical criminal (ie: when a crime has been committed, most frequently homicide, and the entomologist is brought in typically to determine the time of death and if the body had been moved following death.

In both score product and structural forensic entomology, Dr. Goff said the expert is usually called in late and is usually used to determine who has to pay.  In medical legal entomology, Dr. Goff said the expert is usually called in early and is typically used to determine time of death.

Job History/Educational Background:

Forensic entomologist M. Lee Goff is currently retired, but was the director and chair of the Forensic Sciences Department at Chaminade University, where he worked for 13 years.  Prior to that, he was professor of entomology at the University of Hawaiʻi at Mānoa for about 22 years.

Goff said he received his BS from the University of Hawaiʻi at Mānoa in 1966; Masters of Science from California State University at Long Beach in 1973; Doctorate in Entomology from the University of Hawaiʻi at Mānoa in 1977.  According to testimony, Goff was involved in the formation of the American Board of Forensic Entomology, and for the first six years of its existence, he served as the chair of the board.

Over his career, Goff said he was involved in 225 publications and scientific journals, with some 60 articles specifically in the field of forensic entomology.  He was also an instructor in the detection and recovery of human remains at the FBI academy in Quantico, Virginia.

In 2000, Goff authored “A Fly for the Prosecution,” and as a result, became involved in the CSI television series where he served as a consultant for 16 seasons.  Goff said he has testified in Hawaiʻi, California, Washington, Texas, New Mexico, Canada, Australia and New Zealand.  About 25% of his testimony has been for the defense.

Dr. Goff Explains the Life Cycle of a Fly (Diptera):  

According to Dr. Goff, flies are members of the Diptera order, and have one pair of wings.  “One of the things that makes an insect very useful in estimating time periods is that they go through a predictable life cycle.  This life cycle consists of a series of distinct morphological stages.  You can tell one stage from the next,” said Dr. Goff, who noted that temperature can influence rate of development.

“Typically there are four ova-positions (egg laying events) for a female fly.  The first ova-position consists of about 200 eggs, the next two of about 400 eggs, and the last about another 200 eggs,” said Dr. Goff.  “It does not take a tremendous number of female flies to create a fairly large population of larvae, or we refer to them as maggots,” he said.

“This egg is going to hatch and we will have our three larval stages.  We refer to these as instars.  All they have to do is in the first and second instar, is eat and grow.  They are basically going to eat as rapidly as they can.  When they reach maximum size, they have an external skeleton, so consequently, there’s a limit as to how big they can get.  In the first two instars, they will eat and grow and then molt into the next instar,” said Dr. Goff.

“When we’ve reached the third instar, initially, it eats and grows as quickly as possible, but then it reaches maximum size,” said Dr. Goff.  “Everything is under hormonal control.  Rather  than molt into another instar, they’re going to leave the food resource, they’re going to migrate away from it, and basically digest the food, sort themselves, and then they’re going to enter into the pupa stage,” said Dr. Goff.

In the pupa stage, Goff testified that, “everything that used to be the maggot breaks down and you essentially have a second embryology that takes place, and out of that we are then going to have an adult fly version.  And the cycle starts again,” said Dr. Goff.

Dr. Goff said that when the maggots are received, he checks to see which instar or larval stage they are in.  “We have to know how long they are in order to tell where they are in the developmental cycle.  To tell which instar they’re in without any reasonable doubt, we take a look a the posterior end of the maggot,” said Dr. Goff, noting that in the second instar, there are two slits for the exchange of gases for respiration, and three slits in the third stage.

“In order to make our determination, we have to know the species; we have to know what stage of development things are, and what we’re going to do is we’re going to take the most mature specimens and then we’re going to work backwards to determine when the eggs were laid.  That is going to reflect most probably, our minimum period of development,” said Dr. Goff.

Specimens Include 2 Types of Blow Fly Larvae and a Predator Beetle: 

On May 23, 2014, Dr. Goff testified that he received a request for assistance from Maui Police evidence specialist, Anthony Earls.  As a result of that request, Dr. Goff received nine specimen containers of insect larvae on May 27, 2014.

The nine specimen containers included the following: (1) collected from clothing on Feb. 13, 2014; (2) collected from clothing on Feb. 13, 2014; (3) collected from black jeans on Feb. 13, 2014 and placed in refrigeration at 11 p.m.; (4) collected from green blanket on Feb. 13, 2014 and placed in refrigeration at midnight; (5) collected from black skirt on Feb. 13, 2014 and placed in refrigeration at midnight; (6) collected from grey sweatshirt on Feb. 13, 2014 and placed in refrigeration at midnight; (7) collected from nail on Feb. 15, 2014 and placed in refrigeration at midnight; (8) collected from bra on Feb. 14, 2014; and (9) collected from soil indentation on Feb. 14, 2014 and placed in refrigeration at midnight.

“We had actually three species of insects that were present in all of the collections,” said Dr. Goff.  “In two of them were flies from the family Calliphoridae–these are your blow flies, and these were Chrysomya megacephala and Chrysomya rufifacies.  Both of these are very common blow flies in Hawaiʻi and very widely distributed throughout the islands and they are relatively aggressive, typically showing up very early in decomposition,” said Dr. Goff.

“The third species, which was present only in collection 3, which is from the (black) jeans, was a Staphylinidae beetle. This is in the genus Philonthus.  Now this is not a fly–it’s a beetle, but it is very commonly associated with decomposing material; however, it is a predator, and it is interested in the decomposition process only from the standpoint of having available prey in terms of maggots.  So it’s there to eat up the maggots.  It’s typically a fairly early invader of remains, but it’s not something that is really predictable, in terms of–it’s not going to arrive at any specific time,” said Dr. Goff.  

Accumulated Degree Hours: Converting Temperature and Time into Thermal Units 

“Insects, to a large extent are going to be dependent on ambient temperature for the rate at which they develop.  When we find something out in the field, we want to figure out basically how long it took to reach that stage of development,” said Dr. Goff.

“We go first to laboratory rearing data–this is going to be studies that we’ve done at controlled temperatures, and basically we know how long it takes for the first instar, the second instar and the third instar,” he said.

“But, when you find a body, it’s very rare that you are going to find the body in a laboratory with controlled conditions.  So somehow, we’ve got to find a way to extrapolate laboratory data with what happened in the field.  For this, we go to a technique that was actually initially developed by agriculture,” said Dr. Goff, who noted that the technique was first used to predict pest outbreaks.

“Agricultural workers took this and developed this idea of Accumulated Degree Hours to predict pest outbreaks so they would know when to treat the crops,” he said.  Dr. Goff continued,”Our assumption here is that if there’s an adequate food resource, the rate of development for the insect is primarily regulated by the ambient temperature… This is going to be the primary regulator for the rate of development,” said Dr. Goff.

“Accumulated Degree Hours is basically a technique (which) converts temperature and time into thermal units, and these can be used then to correlate laboratory rearing data with climatic data from a scene to estimate a period of insect development,” Dr. Goff explained.

“It’s actually a very simple process, although people manage to make it quite complicated,” he said. “The Accumulated Degree Hours is equal to the temperature in degrees Celsius multiplied by the time in hours.  An example: If the temperature is 28 degrees Celsius and the time is 10 hours, then the ADH is 28 degrees Celsius times 10 hours, and we have 280 Accumulated Degree Hours.”

Dr. Goff said he starts when the body is found and when the insects were collected, takes a look at the development, and then works backwards.

Weather Approximation: Uniformity in Temperature for Low-Lying Areas

“We determine temperatures by going to the closest certified weather station that is available and getting either hourly temperature data, (which we prefer), or daily mean temperatures; and then we use these to calculate the Accumulated Degree Hours that are present at the crime scene.  While this may not be precisely the situation at the crime scene, this gives us a good approximation of what the temperature was in that particular are at that time,” said Dr. Goff, who noted that the weather data he obtained was from the National Weather Service for Kahului Airport, and was provided to him by the Maui Police Department.

When asked if the difference in temperature between Kahului and Keʻanae would have an affect on the analysis, Dr. Goff said, “Working in Hawaiʻi… our temperatures are relatively stable, and while there may be some minor variations from one area to another–in this case if we are looking at low-land types of areas, there’s going to be some uniformity in the temperature, but it may not be exactly the same, or it is going to be still close enough that we can use it to provide an estimate.  If I go up the side of Haleakalā, then we have another problem, because those temperature data would not relate well to the temperature data at the scene, or from Kahului Airport,” he said.

“I converted the temperature data from the National Weather Service Station into Accumulated Degree Hours, then I took a look at the specimens, and based on stage of development and total body length, I estimated where they were in their developmental cycle,” said Dr. Goff, noting that he based his determination of development on data from controlled laboratory studies.

Two Separate Egg Laying Events Identified:

Dr. Goff testified that he determined there were two separate egg-laying events: One that occurred between 1 p.m. and 7 p.m. on Feb. 10, 2014; and a second event starting by 6 a.m. on Feb. 12, 2014.

“In these particular collections, I had Chrysomya megacephala larvae, and these were in the second and also third instar larvae. The largest of the larvae were third instar, and they were 10-12 mm in total length with a mean of 11 mm.  The largest, the most developed group is going to then indicate the minimum period of time that they had been developing.”

“We also had Chrysomya rufifacies, and Chrysomya rufifacies is one that typically comes in very quickly after Chrysomya megacephala.  And here, we have predominantly second instar larvae,” which Dr. Goff said, indicated that they had not been developing as long as the other family of fly larvae.

“Taking a look at the rearing data, (I was) able to determine that basically to reach that stage of development, it’s going to require Chrysomya megacephala 1,950 Accumulated Degree Hours.  So working backwards, from the time that the collections were made,” Dr. Goff said he determined that an egg laying event would have occurred by 1 p.m. on Feb. 10, 2014.  

“The smaller third instar, Chrysomya megacephalawould have required 1,716 Accumulated Degree Hours to reach that stage of development,” said Dr. Goff, noting that those maggots would have started development somewhere around 7 p.m. on Feb. 10, 2014.

“Looking at the relative sizes of the maggots, it appeared that we had probably had two ova-position or egg laying events that took place because the second ova-position and the maggots associated with that, which were all second instar Chrysomya and considerably smaller, would have required 1,014 Accumulated Degree Hours prior to the collection.  This would have indicated an onset of the second ova-positioning occurring at approximately 6 a.m. on Feb. 12, 2014,” said Dr. Goff, noting that the calculation was a minimum estimate.

“When we make our collections, we have no way of knowing if we are at the head of the pack, or at the back of the pack, so we use the minimum,” said Dr. Goff.

“If ova-position had been occurring, during this period of time, in between the two events, I would have maggots present at intermediate sizes, but the fact that I had simply the two more or less distinct groups size wise, this indicates that ova-position occurred, then for some reason it did not occur, and then it occurred again.

Egg Laying Event Consistent with Death Between 9-11 p.m. on Feb. 9

Prosecuting attorney Robert Rivera asked, “With respect to the first ova-position, that you testified began (at) a minimum time beginning on Feb. 10, 2014 at approximately 1 p.m., would that be consistent, Dr. Goff… Lets say a person is killed on Feb. 9th in the evening, between the hours of 9 to 11 p.m. roughly–a person is killed, would that be consistent with the ova-position beginning the next day on Feb. 10, 2014 according to the estimated times you have given?”

Dr. Goff responded with an explanation first saying, “Typically, blow flies are not going to be that active at night.  They cannot fly well at night,” he said.  “They don’t see well at night, so in hours of darkness, they tend to make themselves comfortable, if you will, and they just stay in one location.  They’re not out actively seeking. When light comes up, they become active, and then they’ll go out and then begin looking for someplace to lay their eggs,” he said.

When asked if that would be consistent with laying their eggs the following day, Dr. Goff said, “Yes, it would be consistent.”

He went further to explain that odor and visual cues would serve as the primary two attractants for blow flies.

Lack of Insect Activity for 35 Hours:  Similar Observations Made in Other Cases

In approximately the 35 hours between those two egg-laying events, Dr. Goff testified that there would have been a period of inactivity between 7 p.m. on Feb. 10, 2014, and 6 a.m. on Feb. 12, 2014.

Prosecuting Rivera asked if the inactivity would be consistent with “wrapping a dead body in a blanket and taping the ends of the blanket with masking tape or other material.”  Dr. Goff responded saying, “That would be a possibility.”

“They may be attracted to the body, but they cannot penetrate the wrappings and lay their eggs,” said Dr. Goff, noting that one of three things can happen. “First the eggs may simply dry up.  Fly eggs are very vulnerable to drying and desiccation.  The second thing that can happen is you have a number of predators and that may also be attracted to a decaying body.  The third thing that can happen is that the eggs will hatch and the larvae will be on the external surface.  They may actually remain on the external surface if there is a lot of byproduct of decomposition that is present,” said Dr. Goff.

Goff recalled two cases in which there was a gap in larvae production.  One was on the island of Oʻahu, where a woman had been missing for about 13 days and was found wrapped in two layers of blankets and sealed at both ends with an ace bandage, according to Goff’s testimony.

Goff said he could account for about 10.5 days of insect activity on that body, but noted a two-and-a-half day gap.  As part of the case, he duplicated wrappings on the pig, placed it in his back yard, and determined that it took roughly 2.5 days for the flies to penetrate the wrappings.

Goff said that in a separate case in Washington, a child was killed and left out in a wooded area beneath a tarp.  The edges of the tarp were not weighted down. “In that case, even though there was access to the body, it took approximately two days before the flies went through and laid their eggs on the body,” said Goff.

Goff agreed that the findings could be consistent with someone being killed between 9 and 11 p.m. Feb. 9, 2014.

Case History/Background:

Steven Capobianco is standing trial for the murder of his pregnant ex-girlfriend, Carly “Charli” Scott. He is also accused of setting her vehicle on fire.

Scott was 27-years-old and five months pregnant at the time with an unborn child fathered by the defendant.  Capobianco has pleaded not guilty to the charges.

In the days following Charli Scott’s disappearance, Capobianco had done an interview with police in which he said Scott had picked him up on the night of Sunday, Feb. 9, 2014, and dropped him off at his truck that got stuck in Keʻanae on Feb. 8, 2014.

According to the account, both headed back to Haʻikū, with Scott following Capobianco in case his vehicle broke down again.  Scott was reported missing the next night on Feb. 10, 2014, after she failed to show up for work and did not return phone calls and messages from her family members.

The trial is set to resume on Monday, Sept. 26, 2016, in 2nd Circuit Court.

Wendy Osher
Wendy Osher leads the Maui Now news team. She is also the news voice of parent company, Pacific Media Group, having served nearly 20 years as News Director for the company’s six Maui radio stations.

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